Joanna (Ayer) Barker is listed as a daughter of John Ayer (https://www.wikitree.com/wiki/Ayer-35), however NONE of the sources on his profile show a daughter Joanna, and she was not named in his will although she was living at the time.
Joanna (Ayer) is shown as the wife of Richard Barker, and according to the bio on the profile, they married in England before he arrived in Andover, Massachusetts where he was first recorded in 1643. Torrey shows the marriage as "by 1644", in Andover, but there is no record in Massachusetts of their marriage - at least that I have found. Neither is there a marriage for Richard Barker and Joanna (and variants) in England between 1640-43. Every source I have seen for Richard Barker shows his wife's name as Joanna _____, including in the Barker Genealogy.
Based on all quality sources found, it seems that Joanna (Ayer) Barker should be Joanna (Unknown) Barker. There are MANY online family trees showing her last name as Ayer, though, usually with her father being John Ayer.
Should Joanna's last name be changed to Unknown?
Should Joanna still be PGM? (no doubt she still needs to be protected due to the Ayer name someone will undoubtedly add again for her).