L.A.
A young girls period can be very unpredictable. This is considered normal.
When I was first getting my period, sometimes it lasted 5 days, sometimes up to 8 or 9 days long. And sometimes, they would come every 3 weeks instead of 4.
I was instructed by the Gynecologist to keep a record of how many days and how heavy. Then I would take this to my appointments so they could also record them.
For hair removal and this is only if she wants to shave her legs, , she should be able to just shave her legs with a razor. . You can teach her to either use soap or shaving cream. Remind her he does not need to press hard..
I have always had dark hair so electric shavers never worked for me, but it seems women with light hair, have good luck with them.