My 2p.
Make sure (I'm sure you will from what you've posted above) that she is not seduced by brand names, pretty colours and/or flashy stickers (including 98% off!
). Ensure that she test rides each of the candidate bikes properly - I mean at least 1/2 hour on each one, not just sitting on it in the shop. Then buy the one that fits best.
The bike that doesn't fit will never be a bargain. The "pricey" bike that fits, and that she enjoys riding will be a great investment.
Money spent on contact points is rarely wasted either.