When I started sewing for babies, I bought a book called Making Children's Clothes by Emma Hardy. I've made several items from it with mixed results (sizing is all over the place). One pattern I have made several times, the nightgown. It is so cute and fits a long time.
On my most recent fabric shopping trips, it was Eleanor and I, and to help keep her happier longer I bribed her with getting some fabric just for her. We picked out some cute polka dot apple (Eleanor calls them strawberries) flannel. It sews up really fast.
The pattern has long sleeves, but I had to do short, since I didn't have enough fabric for it, which I realized after I started cutting. I like it none the less.