Taking longer to fall asleep

08summerbride

In the past week or so it has been taking DD longer to fall asleep.  She is not fussing in bed, just doesn't seem to be relaxing as quickly. We have always put her to bed awake, but in the past she has fallen asleep within 5 to 10 minutes of her head hitting the sheets. Recently however, it is taking 30 minutes or so.  We haven't changed anything in our bed time routine, and she doesn't seem upset, I just feel a little guilty with her awake in her crib for 30+ minutes, if that means I could be enjoying the time with her. Does the restlessness mean she is ready for a later bedtime, or is this just a phase? She has been going to bed at 6:30 PM since about 6 months old, and the past few days I have tried closer to 7, but I am not sure how far to push it. I definitely recognize the importance of sleep, but don't want her to have to lay awake in her bed for 45 minutes before falling asleep if she isn't tired either.