Not necessarily. As your LO gets older, she might need shorter naps, but she also might not. Your EASY may stretch out a bit past four hours as time goes on (especially as you add solids into the mix and regular meals). Also, you may end up with one shorter nap and one longer nap....and eventually just one nap all together. Basically, if she's happy and you're reading her cues, don't worry about it.