If you are not able to verify what the person’s full name is, then cite the work using the title Mrs. and the rest of the name given on the work. Some works published under what looks like a married name may be pseudonyms intended to disguise the identity of the writer. In your entry, do not invert the name. Here is an example of how the entry would look if you could not verify the full name or if the name is a pseudonym:
Mrs. Henry Wood. Anne Hereford: A Novel. Tinsley Brothers, 1871. Project Gutenberg, 9 Sept. 2018, www.gutenberg.org/cache/epub/57875/pg57875-images.html.
If you are able to determine the author’s full name, you may cite the work under the person’s full name and include the alternate form of their name in square brackets, preceded by published as in italics.
Wood, Ellen [published as Mrs. Henry Wood]. Anne Hereford: A Novel. Tinsley Brothers, 1871. Project Gutenberg, 9 Sept. 2018, www.gutenberg.org/cache/epub/57875/pg57875-images.html.