Deerclops, the first boss where wendy's damage modifier really needs to be considered, is able to kill abigail in five hits. Abigail will not dodge deerclops. This is one of many situations where wendy won't be able to compensate for her lower damage, and there it really matters. I completely disagree that wendy has no downsides, and that recent changes have made for fewer and fewer downsides. A lot of characters have negligible downsides! The oldest character to have any awful ones is webber.
It has always felt weird to me though that wendy's only downside is that she's worse in combat while her upside is that she's better in it.