Last summer DD had 3 sets. Granted she was at swim class every week but I thought even 2 would've been enough for a baby! (she was 6-9 months)
This summer I'm thinking I should get 2...? Or I wonder if she'd be out in the backyard playing in her little pool much more... She'll be 18 mo in June, but it probably doesn't really get hot here till July and I'm unsure if we can afford more swim lessons for her.