Some women's bib shorts I've seen seem to have straps in the normal place (i.e. like men's bib shorts), so they'd go right over your boobs.
Whereas more expensive ones have an arrangment that pops down your cleavage instead.
It may depend on your size, I certainly would have to go for the latter as I can't imagine the former being comfortable (but then again, I don't cycle in anything less than a level 4 sports bra because anything less is scarily [and painfully] bouncy!)
You probably need to get somewhere and try things on.
Edited to add: This thread is absolutely fine without pictures, actually.