Sometimes, errors in biographies or other writings about history creep in because someone's made assumptions and got a bit confused. Two examples, one of some details about a minor women's history figure who I just happen to find fascinating and have done a lot of research on, and another example of some confusion about a better-known figure's accomplishments:
Anna Garlin Spencer's Ordination
In writing (offline) about the minister and activist Anna Garlin Spencer, I found that in Who Was Who, her ordination date was listed as a different date than it was in her own history of the event. The date given as her ordination in Who Was Who was the same as the date she gave as the dedication of the church she served -- which was earlier than her ordination. I figured that her own memory was probably more correct. I found a letter in a file at a school where she'd taught where she was asked to comment on her ministerial records, and she had handwritten a date and what at first glance looked like "ordination." But on closer look, she had written "dedication." Yes, those two don't look a lot alike in type, but in her scrawly handwriting, I can see why it was confusing.
In that same document, as well as in several letters I found, Spencer specifically denies being a "Unitarian" minister and states that she prefers "independent" minister. Yet encyclopedias list her as a "Unitarian" minister and I've seen others use the encyclopedias as final authorities -- despite her own wishes on the matter!
Mary Church Terrell's Organizations
Mary Church Terrell played a key role in founding the National Association of Colored Women (NACW) in 1896. This organization came about as a merger of black women's clubs. Terrell held the presidency until 1901, and then was appointed honorary president for life.
In 1910, as part of her involvement in the world of education, she helped in founding the College Alumni Club (or College Alumnae Club, I've seen both names used in documents). This evolved into the National Association of College Women which shares the same acronym, NACW, with the more famous organization she founded in 1896. In 1974, well after Terrell's 1954 death, the National Association of College Women evolved into the National Association of University Women. (That could also be confused with the American Association of University Women, which rejected Terrell's application for membership in 1946, then accepted her membership in 1949.)
So I've seen profiles of Terrell which confused the two NACW organizations, and have her founding the National Association of College Women in 1896.
Why Consult Multiple Sources?
It happens not just with women's history, but with historical writing in general -- but perhaps it happens a bit more frequently wherever the people and organizations are not mainstream and therefore unfamiliar to those writing about them.
All of which is to emphasize the importance of using multiple sources when writing about women's history (or any history), which increases the chances that you'll find the correct version in one of the sources. But, because one of your sources may be based on the other, or they may both be based a common source with the mistake, it's especially important to try to find original sources -- documents, first-hand accounts, autobiographies, and so forth. Be especially wary of such sources as Wikipedia, where the authors are anonymous and may not be experts -- and may not be informed enough to avoid these sorts of mistakes.