I am curious about this also. Since the woman's surname was more likely to have changed each generation the women somehow seem to be difficult to adequately represent. This is not meant toward ancestry but there seems to have been a historical unrepresentation of women's lines that you see even in current works. I suppose part of this was bias, in the past, toward men and more was written about them. Another part of it was the difficulty following the name changes. I had thought that I would receive a lot of matches for my mother's side(since I am female and it would follow my maternal line) and have received far more for my father's side. Even the matches found for my mother's line almost seem break out of my maternal line and end up with the male side.
Also, the spouses do not seem to be showing up as matches. Again, it appears to be the women who are primarily under-represented, although not every time.
Could this be because the trees have not focused on the women's lines enough or is it still difficult to track the woman's lineage with DNA?