Photographers that shoot for Elite in NY get $375 for a test.
Without knowing what sort of model she is, it is hard to say what she needs in a portfolio.
If she is going to be going to open days at agencies, then a simple headshot will do. If she is sending images in via email. A headshot, straight on mug shot style and profile. Hair down and then pulled back. Full body shots straight on and profile in a bikini. These are basic images that any agency will appreciate. If the model as potential most agencies will cover the cost of a session with a photographer. Of course most agencies will recover that cost from future bookings.
Make up should be Chapstick.
Of course if this is a vanity project, get a whole crew, with a MUA, Wardrobe stylist, property master, and location scout.
Back to reality. You might have her pick up a copy of:
The Complete Idiot's Guide to Being a ModelSounds funny but it has useful, factual information.
I hope this helps.
Bill