Yes, it is. As your daughter’s intestines mature and she is able to digest your milk more completely, the amount of waste she produces is decreasing—which means she now can go for days without having to poop. This pattern often begins at about 6 weeks of age and can continue while a baby is exclusively breastfed.
Now for the caveat: If your daughter seems to be very uncomfortable when passing bowel movements or if she is having hard stools, be sure to talk with your pediatrician. But if she is growing well, smiling, peeing and pooping without pain, everything should be just fine.