Bathing suits

Amber • Having baby #1! So excited(:
My baby is due in July and we are going to Florida in December and I want to buy her a bathing suit. I found a really cute bikini and I wanted to get it for her, but one of my friends told me your not supposed to put them in bikinis, and that they need to be covered up. So my question is what is yall's opinions? She'll be 5 months old by December.