I say, "Never wake a sleeping baby!!" As long as she is happy, healthy and developing normally, she is probably fine. She is probably just going through a growth spurt. My son, who was only breastfed for the first several months started sleeping 6-7 hours straight by 2 weeks and was sleeping 10 hours straight at night by 6 weeks (consistantly). He was healthy, growing, and developing normally so I figured why would mess with his good sleep habits to have him feed every 3 hours?!! That would just get him in the habit of waking up to eat even if he didn't need it!! I figured he would wake up if he was hungry enough... but he never did... just cluster fed from 5pm to 9pm, but that was fine with me! I say let her sleep, atleast at night. You might want to try to keep her up a little more during the day. She is at the age where she might like some new toys, tummy time is important etc. Sing little songs with her or give her a massage... she might like more stimulation to keep her occupied....