It is different all round.
DD1 was a poo every feed - without fail - until almost 2! DD2 would go hours and hours, usually on one poo a day, until 12months old, now it varies between 2-3 a day to none for 2 days.
What you are describing is totally normal to me. It is exceptionally unusual for a BF bub to be constipated, but they do get gassy - which can be caused by all sorts of things like too much air when feeding, your diet for example.
You can try giving her a warm deep bath every day, lots of leg kicking around on the floor with you, letting her move around will help get things going. Massaging her tummy gently, in clockwise circles, and cycling legs can help too.

All in all though, she may maintain her current feedoo ratio, it may change, it may change every week, they are all different. If you go more than 4 days without a poo and she is in pain or straining, or there is blood in her stools, then I would start to be concerned.