However, doing any calisthenic exercises should be fine. Almost anything re BB/DB would be ok for Chest, Back (except deadlifts; I would do romanian deadlifts), Shoulders, and Arms, as long as she's not having to bend down or squat too much (this will be ok once she loses some weight). Abs exercises get her doing planks, and things like that.
As a beginner, I would start her off at one set of one exercise per body-part, and do that 2-3 times a week.
Re weights, get her to use something she can do for 10-12 reps, but no more (and if she can't get to 10 reps, then decrease the weight).
Progress exercises, sets, reps, etc., when she can.