I agree with the other ladies. The milestones & growth spurts always interupted Allie's sleep. That being said, my child only STTN for a 2 week period when I went back to work at 3 months.

If she is going through a growth spurt, she'll be hungrier (and crankier) than usual so you should definitely offer her the formula.
Good luck & I hope things get better for you soon!