Hi T.,
I agree with everything that Suzy R said. I can tell she is a compationate person. I must say, that the EXACT same thing happened to me when I went back to work. I did not have any Nanny issues, because my son is being watched by his grandma and grandpa, who make sure he is getting enough to eat and sleep...and quite frankly, they rarely let him cry for more than one breath (more like a grunt). Ha Ha.
Anyway, my son is now 13 months old and still wakes up every two to three hours and I've tried everything the other people suggested...more food during the day, etc.
I'm convinced that he just wants to be close to me at night since I cannot be close to him during the day. I'm still nursing, so I find it mutually beneficial for him to drinka little bit a few times a night, so I don't have to pump.
Anyway, the best advice I can give you is get a fully reclining Lazy-Boy chair...best investment we made. When my son wakes up, I quickly pick him up before he even knows he's awake and sit in the chair and nurse for about 10-15 minutes. Before you know it, he's back to sleep and I lay him back down in his crib. 15 minutes isn't enough time to really wake up, so my body has learned to adjust...and I fall back to sleep.
As my grandma would say, "this too shall pass." They are only this young and vulnerable for such a short time...enjoy it and roll with the flow and try to sleep when they sleep.
I don't know if this is the right thing to do...I've read a lot of books thay say your should let them cry...so they can learn to self soothe. I've decided that I just cannot do that. He needs me for some reason at night and I've decided to be there for him (no matter how tired I am).
I hope you find some peace and a the happy medium between your needs and your daughter's needs.
Someone told me once...it's not like she'll be waking up every two hours when they go to college...so, eventually, she'll get it worked out. :)
About the nanny...I agree...any nanny that doesn't think a 4 month old needs a least 2 naps, if not three or four...isn't a good nanny.
Good Luck and sweet dreams!!!
B.