Ok, could it be that the sleep ritual is too long for her and that she doesn't even want it?
I need to put my LO straight away in bed, or he starts crying. With some babies less is more. The ritual might be even stimulating her and she is then OT.
Your pattern sounds fine to me (EASAE), many moms do that and I am one of them. If you think she is ready for the 4h routine, do it gradually. Start with a 3.15h, then move to 3.5h and so on.