Kelly its hard to know, things get pretty confusing sometime with these wee little ones. I know that developmentally they go through changes at 12 weeksish... Some start to roll & there are other milestones that they can reach at that time which can cause them to be unsettled. Its also a time for a growth spurt too, which would cause her to wake more frequently.

Also they become more "aware" of their surroundings the older they get, so changes in routines can disrupt them. Depending on their personalities... Matilda is a very routinised girl who loves her routines, unfortunately DH & I are very "unroutined" people so we've had to learn how to fit together as a family...

Matilda was just starting to sleep for 3 hours at a time rather than 2 at 12 weeks and her sleep started settling just after then.

I don't have much advice but hopefully it won't last too long!