After _The Fatal Friendship_ Miss Trotter's work for the stage need not be particularly dwelt upon. She had a comedy brought out at Drury Lane in 1701. A new tragedy in the same year at Drury Lane, and a tragedy at the Haymarket in 1706, complete the list. Some occasional poems appeared during this period. In 1700 she was one of the nine ladies who wrote on the death of Dryden, under the title _The Nine Muses; or Poems written by as many ladies on the death of the late famous John Dryden, Esq._ In 1704 she entered the lists with Mr. Addison and Mr. John Philips in celebrating the victory of Blenheim, but she did not venture to publish her poem till the manuscript had been submitted to the Duke of Marlborough. When the duke and the duchess and the lord treasurer Godolphin declared themselves "greatly pleased" she sent her lines to the press. Besides her dramatic and poetical work Miss Trotter wrote in prose on critical and theological subjects. An interesting disquisition on "the poets of the last age" appeared in the dedication of her _The Unhappy Penitent_ in 1701. Of Shakespeare, Dryden, Lee, and Otway she speaks with independent judgment and considerable discrimination. But none of the works so far listed are those on which her fame rested. It was not in poetry, drama, or literary criticism that she found satisfaction. Religion and philosophy were her true field. Locke's _Essay concerning Human Understanding_ was published in 1690, and among the antagonistic criticisms it called forth were three series of _Remarks_ published anonymously in 1697 and 1699. Young as she was Miss Trotter pursued the controversy with the keenest interest and in 1701 she drew up a _Defence of The Essay of Human Understanding_. Mr. George Burnet of Kemney, then in Holland, and Mrs. Burnet, the wife of Bishop Burnet, were entrusted with the secret of her _Defence_, and both advised anonymous publication, agreeing with her that her youth and sex would, if known, count against a work of that nature. Her _Defence_ appeared in print in 1702. Mrs. Burnet on finding that the Bishop, Mr. John Norris, and Mr. Locke himself, were highly pleased with it, could keep the secret no longer.[161] Mr. Locke sent Miss Trotter a present of books and a letter in which he expressed his gratitude for "an opportunity to own you for my protectress, which is the greatest honour my Essay could have procured me. Give me leave therefore to assure you, that as the rest of the world take notice of the strength and clearness of your reasoning, so I can not but be extremely sensible, that it was employed in my behalf."[162] A second pamphlet was entitled _A discourse concerning a guide in Controversies_ and grew out of her own spiritual conflicts. Although of a Protestant family she had become a Catholic early in life, but had gradually found herself less and less in harmony with that church till 1707 when, in this _Discourse_, she announced her return to the Church of England.