Totally and completely normal!!! Sounds like she is doing awesome and is perfectly ok.

Leila was the exact same way when she was a baby. She eventually spread out her poops to once a week or so. Could be a couple less days or could be as much as 9 days between feeds.
A hungry baby will let you know. She will either cry and cry or she will be super lethargic and hard to rouse. Sounds like you have great breastmilk that her system is getting every ounce of nutrition out of before passing it. Keep it up!!