Every few days is not uncommon for her but I'm starting to worry at 7. Her farts are out of this world, OMG but she doesn't seem to VE straining. A little fussy, but that could be a phase.
Shell be 6 months old on the 10th. No solids, EBF.
All 3 of mine would go 10 - 15 days when they were EBF (they all started solids around 6 months). You can use a baby supository if you like, but I found my kids still did not usually poop with that.
My DS went 21 days without pooping when he was about 3 months old. It isn't uncommon for EBF children - they are just using every bit of what they are getting and there is NO waste. When you think about it it is really pretty amazing that our bodies can do that.