I feel a bit foolish asking this but this girl thing is new territory! Ds used to wear a washable swim nappy but the pool was so cold . So I bought dd a all in one suit . Should she be wearing something else as well in case of poop ?
We use a Happy Nappy swim nappy which has close fitting leg and waist bands to prevent poo escape (not that he's ever pooed in it). I've never used anything else underneath but I did need to buy him one several sizes bigger than they said as his eyes would have protruded with the tightness of them otherwise. I bought him an XXXL when he was (a very chubby thighed) 6 months and it still fits him now (his thighs have halved since he started walking).