Mary Talbot was first tried at the Old Bailey on 27th February 1788. She was convicted of stealing a piece of linen and sentenced to 7 years transportation. She was one of the female prisoners placed on the Lady Juliana transport which was to convey convicts to New South Wales, however when the Lady Juliana departed England on 29th July 1789, Mary Talbot was not onboard. The Times (London) reported that she, with many others had escaped from the vessel.
Mary was retaken, and on 13th January 1790 was again tried at the Old Bailey for 'returning from transportation'. She received a sentence of Death with recommendation for mercy. After finding that she was with child, her sentenced was stayed and she remained in Newgate prison.
In December 1790 the London Times reported that she was on the list of capitally convicted prisoners who had received His Majesty's pardon on condition of being transported to New South Wales for their natural lives; except for Mary Talbot, who said she had rather die, as she had three infants, and it was that which made her return from transportation. The Recorder pointed out the fatal consequences in vain; she persisted in dying, and was taken from the bar in convulsions. 
She was eventually transported on the convict ship Mary Ann which departed England on 16th February 1791. While at St. Jago on that vessel she wrote a letter which was later published in The Times:
The Times (London, England, Tuesday October 18 1791
Following is a Copy of a Letter from one of the Female Convicts to a Gentleman in England, who had exerted himself very humanely in her behalf, to get her the Liberty of transporting herself and Family to America, though without success; giving an Account of her Passage to St. Jago, on her way to New South Wales.
St. Jago, March 29, 1791
Most Honoured Sir,
"Your past kindness to me, induces me to trouble you with some account of where I am, and what kind of voyage I have had: - the latter, however, cannot be a very favourable one, for we have been surrounded by dangers. We sailed from Portsmouth the 23rd of February, with the wind much against us, and were so much in danger, that we feared we should have shared the fate of a ship which was lost within sight of us.
Our good Captain very kindly dropped anchor at the Nase, but did not stop more than one night, and sailed for the Downs, where we sent our pilot on shore. On the 25th and 26th, along the Coast, we had a violent storm, which lasted 24 hours; during every moment of its continuance we expected to perish, and were washed out of our beds between decks, while the sea-sickness and the groans and shrieks of so many unhappy wretches, made the situation we were in truly distressing; for there were 138 women and five children; two of the latter born after we sailed, and one only died on our passage hither, where we remain no longer than is necessary to repair the ship and taken in water. Our Captain hopes we shall arrived at Botany Bay in August, if it please God the weather should prove favourable. This is a very fine island, supposed to be very rich, but the inhabitants I have seen are principally Blacks. The general produce is poultry, hogs, and goats, which are very fine of their kind; and rich fruits, such as oranges, melons, etc., are very plentiful and cheap.
The 16th of March we crossed the Line, where we were dipped in a tub of salt water by the sailors, and tarred all over; it being a rule amongst them to make every one pay so much money, or undergo this, and we all shared the same fate. I have been greatly distressed for want of money, because I came away without being able to see my husband.
"If, Sir, you have any success in your application for my pardon, you can send it me by any of the Captains coming out to Botany Bay, which I am sure your goodness will endeavour to do for the sake of my motherless children; they are the only cause of my anxiety and unhappiness. I hope your generous exertions, aided by the goodness of God, will one day restore me to them, whether you succeed or not, that God I sincerely hope will reward you, fully reward you for your past unequalled kindness to me. Pray Sir be good enough to let my husband know you have had a letter from me, and beg him to take care of my dear children. I think it hard I did not see him before I sailed, for we laid a week at Gravesend, and I should have left my country less sorrowfully had I given him my last charges, and bade him farewell.
"If you will send to me, Sir, directed to be left for me at Governor Phillip's , New South Wales, and say anything in behalf of my character, it will serve me much; and if you can write immediately, the letter will be there before me, and mention that I am coming in the Mary Ann Frances, Capt. Murrow, because your recommendation, in the most trifling degree, will do me great service on my arrival.
"I hope you will excuse my being so troublesome to you: I sent you two letters from Gravesend, and mentioned my going to send one by the Barra, but as the man never came, I hope you did not send anything. You, Sir, are the only friend I ever had in my afflictions , and I remember your goodness without grief, except when I reflect that I have no reward to offer you but my humble thanks.
"We are much better off than I expected, and have as much liberty as our unhappy situation possibly allow. I am much better in my health than I have been for some time, and with God's assistance and yours, I do not despair of yet living to be a comfort to my children. This, Sir, is the only prayer for herself in the heart of one bound in duty and by gratitude to pray for you and your family as long as her life and heart have power to think of, or utter a prayer to God; and who is your most humble and obedient Servant,
*We have given the above unfortunate woman's letter a place in our Paper, as her case is of that nature to interest us in her behalf. It appears that she was tried for stealing a piece of linen from a shop in Tavistock street, ( the only theft she says she ever committed), and was sentenced to seven years transportation. When the vessel was at Gravesend, a man, whose wife wife was a convict contrived by a boat to get them on shore from the ship and she was retaken some time after, and sentence of death pronounced for returning from transportation before her time; but after laying in Newgate near a year, received his Majesty's pardon on condition of going to Botany Bay for life, which she refused at the bar on account of not being permitted to take her children with her, and was taken back to Newgate in strong convulsions, and her shrieks were re-echoed through the whole gaol. The occasion of her committing the theft from her own and her husband's account was as follows: They were natives of Ireland - he was be trade a stone mason, but on coming to England, entered into the service of a Merchant in Austin Friars, where he continued till after they were married, when he returned to his trade, and had worked with a stone mason at the West end of the town near two years, when he had the misfortune to have a stone fall on him, and was carried to St. Thomas's Hospital; that during the time he was there, having nothing to support herself and children, she committed the theft of which she was convicted. That fearing it might disgrace her husband, she was tried by her maiden name; that after she escaped she secreted herself till her husband could procure means of their returning to Ireland; but venturing out one evening, she was recognized by one of the gaol runners, and unfortunately taken hold of.
Mary Talbot died in 1791, not long after she arrived.
 "The case of Mary Talbot, who refused the King's pardon last Sessions, we understand to be." Times [London, England] 24 Dec. 1790: 3. The Times Digital Archive.
 "Old Bailey." Times [London, England] 20 Dec. 1790: 3. The Times Digital Archive.
 "The following is a COPY of a LETTER from one of the FEMALE CONVICTS to a GENTLEMAN in." Times [London, England] 18 Oct. 1791: 3. The Times Digital Archive.