Honestly, non-existent. I mean as big as she may be, some of the fabric will be showing, and she can always "prove" she is covered up where it counts if the establishment ask. I have seen wonderfully large ladies in practically dental floss when I have been swimming with my son, and they have never appeared to have been "pulled up" or "called out" for appearing to be naked!
I would tell her to go for it. Life is too short for worrying about the small stuff. So, as long as the fabric can cover "the girls" not entirely, but at least the nipples, I think she will be fine.
(The "feminist" in me still thinks it's insane that a man can flash his moobs all he wants, but apparently a woman's breasts are practically pornographic, but I digress here!)
6 years
