Buttercup has partially the right idea, but since you asked her instead of her showing interest herself (and since you have under a week to begin), start but don't end there.
At T - 6 (or 5) days, give her the PHB, tell her what sections to look at (especially classes, races, and tell her to glance at feats and skills to get a minder, but not to agonize over the choices.) Let her mull over everything, and after 2-4 days, casually ask her what sparked her interest in the book. Don't press, though, just use this to get an idea for...
Some time before game, either the day before or if you have a couple of hours ahead of time, have her over to work on her character. Unless she's deadset on one of the choices, steer her away from the Cleric and Druid, and probably away from the Wizard too. (Playing a spellcaster can be tricky, and especialyl for a new player the sorcerer or bard is easier to remember. Fewer spells to keep track of, and you don't have to pick up what's good to prepare when.) Ideally, you'd have her in a class with a good hit die, but you want her to have fun with the concept more than be mechanically sound. (Read: if she's waffling between two choices, encourage her towards the more combat ready one, but don't make her feel that she "has to" play something.) Races shouldn't be too much to worry about, but have her pick skills in a featlike manner. (The PHB optional manner; show her a list of skills, tell her to pick N + INT mod of them that she likes, and max all of them out.) I'd also reccomend giving her the PHB package gear, just to gloss over the problems there.
When you have all the essentials of the character skeleton, use the character sheet in the back of the PHB, or any other very good one that gives a space for every modifier. Explain to her how everything works out, but at the same time, leave her with enough "when I ask for this, you roll and add this" room, and let her figure out how it's derived later. She doesn't have to understand it all at one gasp, just the basic modifiers she'll need to get started, and the rest is all practice.