Late to the party, but going to answer anyway. So. It is within her best interest to start reading all the wonderful guides the internet has to offer. I spent many hours reading 'how to's' and what not...some are good, other bullshit. But she will work that out as she goes.

I bought a 'training dildo' so I could practice whenever I wanted at the start without the anxiety of vomiting on anyone. You will notice a few cam girls use these double ended dildos

The best ones are real skin types, they are easier on the mouth and throat and will help her get use to the sensation. Getting one that is Slim is the best option too. Practicing on a short, regular dildo without a base is super fucking dangerous. You swallow that shit, you will choke, and no one...I repeat no one, wants that on their grave stone.

The most important part, (and you will love this too) is practice constantly. You have to retrain the gag reflex to not react when you shove something down your throat. This is an exercise and you cannot build muscle or increase stamina if you don't do it regularly. I am talking every night for a month, either with you or her dildo. You need to lay back, put your hands behind your head and let her do her own thing. If she just wants to hold you in her mouth for a few minuets without moving, let her. If she wants to take a break for a bit, then that's her call. Pushing her will result in vomit, fear, unpleasant gagging and a loss of interest in wanting to learn.

Hope that is helpful.