I agree, some practice is in need in some safe places, I was waiting to see a car come skidding round at her. Luckily only pride would have been hurt from the looks of the vid.what a trooper. but some things that should help immediately.
stop looking down when braking and make sure the bars are straight! When stopping both feet down. When pulling away, paddle walk 3 or 4 steps. It's perfectly ok. She doesn't have balance and she's got one leg up on the peg. She's also trying to pull away at an angle (turn and start). First get rolling in a straight line, then add steering inputs.
We don't have engine audio but I expect she needs a clinic in clutch and throttle coordination. Add some gas, hold the RPMs up and feed in some clutch to get rolling.
several of those are on streets where she could easily have gotten nailed. Go find a nice, empty parking lot with some islands, or the cul-de-sac in your community and practice starts and stops till she does better than 9 out of 10 correctly. One lesson I do is have the coach pull backwards on the rear grab rail and the student has to fight you with throttle and clutch to keep the bike from going forward or reverse.
Can she reach the ground comfortably with both feet? Doesn't need to touch the heels but shouldn't be high on the balls of her feet. No good shots in the video to tell. I would also have her practice putting some mojo into those legs when coming to a stop. I don't think she's actually prepared to stand hard to arrest early-onset tipping motion. You can help by having her sit upright and pushing sideways on the bike and make her react and catch it. You control a bike with your inner thighs. Once she stands up and out of the saddle she has disconnected and lost control of the vehicle. Stay in the saddle and use those leg muscles.
Does she pick the bike up when it falls over or do you?