A.C.
I am having the same issue. I'm trying to change up the music and soothe my 4 monthold in the crib to help her goto sleep. I think it's because she is more aware of what's going on so it's time to change up. I've moved her bedtime up and taken out her thrid nap yesterday. I found that my daughter is a late person and I just can't fight it. Maybe there's something that your daughter is doing that you're maybe not paying attention to unwittingly. See if you can help her go with her flow. I don't know if that helps, but good luck, to you and me both!
A.