I remember DS had a slight sleep regression around 11 weeks. It was right before I went back to work and I got kind of panicked. After a few nights though he got back into a routine and all of a sudden started sleeping for 10 hours at a stretch (which lasted until the 4 month mark and then bam, no more STTN....sigh).
But yeah my advice is just ride it out. Will rocking her in the glider or putting her in a swing help? for some reason on DS's really rough nights we could never get him back in his crib or co-sleeper but H could get him to go to sleep in the swing or the bouncy chair, which I couldn't do.
Sounds like a growth spurt. Can you side lie nurse in the co-sleeping bed? It could also be that she is more distracted eating during the day so needs more calories at night (reverse cycling). If that's the case try going into a dark quiet room to nurse during the day to help her eat more. Good luck! It's hard to be a great mama when you don't sleep. Hang in there.
Starry, DD is doing the same thing. I was getting 8 hour stretches from up until Thanksgiving. Naturally it started right before I went back to work. I'm chalking it up to a growth spurt and hoping it will be over soon. She turns 3 months tomorrow.
all I read is that babies should be starting to consistently sleep long stretches around now and that it is your fault if they don't.
Sleep books suck. They gave me so much stress that if I just did some magic thing, I'd get to sleep all night. From the other side... I really don't believe that was true. DS needed me for longer than some babies need help at night, and that wasn't my fault.