Just warn her. People figure it out. She'll probably cut herself a couple of times by bumping against the edge, but these cuts from "too sharp knives" are usually minor league.
Dull knives cut people by forcing them to use a lot of force ... and then if something slips, the knife is moving with a lot of speed and can cause really nasty and deep cut.
I think the bigger issue is the longevity of the edges. There's no use handing someone a very sharp edge that's going to get damaged after 5 minutes of use. If you're sharpening for someone who has neither excellent knife skills nor excellent sharpening skills, the emphasis should be on a functional, durable edge that's easy to maintain. This can mean a relatively obtuse bevel angle, or a thin angle with very obtuse microbevel on one side. In either case, how you choose to set the bevel will determine how you teach her to maintain the edge.
I see zero benefit in just dong a bad job (or sabotaging a good job) in the name of safety.
