I agree with you she shouldn't feel trapped into being the breadwinner if she isn't comfortable with that, and evidently she isn't.
Not sure I like the "black tax" label much though, this is something that happens to folk of all colors, I think. We will never truly fix problems affecting all at source, if we are always only looking how to fix them for a selected group, surely. Labels like these probably actually originate from sources who really don't want to see the problems fixed, since fixing them would affect their privelige, or their jobs.