I would strongly suggest that if at all possible, she tries before she buys. I also have every manual cutting machine on the market and it may be too difficult for her to turn the handle. You get a bit more leverage when standing. There are electric versions (where the handle is turned for you, like the Sizzix Vagabond) which are pricier than the go! Sizzix machines take sizzix dies, and can accommodate go dies with a home made shim. There are also electronic (computerized) versions, but you can only cut one layer at a time.
I would use precuts and/or see if a local quilt group would be willing to cut for her.