I'd probably send your DD with some UK-only stuff as gifts for the family - if they're expats themselves, ask them what they miss most and would like.
Other than that, what others have said - train her in the arts of being a good houseguest - how to help with cleaning, cooking, doing her own laundry (with permission) if she can't already, that kind of thing.
Also, get her to join the YHA before she goes - because if she does start doing any backpacking, it may get her cheaper accommodation (it used to), and she may get reduced entry to various things as well.
Another point - clothing out here can be viciously expensive as well, so she shouldn't expect to be buying too many clothes out here if she can avoid it - get her to bring a decent "capsule" wardrobe, everything washable.
If she has problems with insect bites, get her some antihistamine cream in the UK as well - they don't sell it out here at all, only antihistamine tablets.
Hope she manages to get a job and has a great time!