A great theme for really young kids - girls or boys - is to do a stuffed teddy bear theme! You should only have to raid the toy box to decorate!
Fuzzy teddy bear invites! Source: my party file
Great your guests with a big teddy bear! Or setup a little photo op! Source
I love the cart used as the decoration and the huge teddy bears, I am sure, will get great reviews from the little ones! Source
I love the colors and balloon wall in this setup! And TOTALLY sold on the banner with the Teddy Bear silhouette! Source
I am not sure I could bring myself to eat these little bear breads but aren't they too cute not to make?! Looks like you just need dinner rolls, pinch up two parts for ears before baking and then use edible markers (here) to draw on eyes and a nose! Source found via edible crafts blog