Depends what you want to achieve etc. Check out this thread from a few weeks ago.
Here's what I said:
- what are the key training aims (if any)
- level of resistance
- want to be able to change resistance on the fly (and emulate slopes etc)
- want to hook up to a computer and track stuff like HR, cadence, speed, watts, etc
- want to record sessions for comparison
- floor space (and portability)
- want to be able to use it anywhere, e.g. indoors/outdoors
- want to race against other people (online?)
- want to ride virtual tracks/routes as well as pro routes
Answer those and you get might some more pointers. Sounds at the mo that she just needs an entry level jobby. If so, I'd recommend talking with Fudge Cycles and Cycle Sports UK.
I did a lot of research end of last year before opting for Taxc Flow 2200 with the PC upgrade kit. Excellent piece of kit but around £500 (in the sales). I can do everything listed above plus create routes using Google Earth (except virtual racing - can't be bothered with that).