Babies get more and more "wired" the less sleep they get, so she may seem very happy and excited with no naps. Her day sleep patterns are still emerging, but by four months or so you may want to try and estabish an a.m. nap around 9 a.m., a p.m. nap around 1 p.m., and a catnap around dinnertime. She may never be a long napper but she does need to nap.