That's bikini H is in is soo unflattering. She should wear a bikini that properly fits her and she would look amazing! It's not fat shaming but it's the fit of the clothing she wears that don't do her any favours.
A person only needs to change their body if they personally wants to, but at least dress for your shape. I know if I wear something that isn't flattering I feel soo uncomfortable. I can see the difference in my overall posture and behaviour in photos when I'm wearing flattering clothes compared to things that are on the tighter side or don't fit nicely.
It's not to say wear a bin bag, but size up at least as it makes all the difference. No one will know or care what size of clothing you have on, but it will look so much better.