From experience girls typically look after themselves when it comes to periods.
We keep a supply of sanitary towels in our HQ, all the girls know where they are if they need one. We always take a supply to camp. Again it's part of the arrival briefing to tell the girls where they are. Very occassionally one of them vanishes, presumably a girl who gets caught out and goes to grab one. I only recall one occassion where a girl has actually asked for one. The conversation went broadly,
Scout - "I need a sanitary towel Skip, where are they?"
Me - "Store room, middle shelf, next to th