On a recent trip to the pool we forgot to bring a change of clothes for Lillian to wear after swimming. The solution, wear her brother's 18 month size clothes. His clothes actually fit her quite well despite the fact that she normally wears a size 6. After that realization Lillian was excited to put some of her clothes on her little brother so they could both wear each other's clothes. A size 5 t-shirt and shorts seemed to work OK for the little guy, and he only looked a little bit girly.