Yes, look at sites like EnableMart and RJ Cooper for low-force ability switches. Depending on her abilities, a head mouse, tongue mouse or eye gaze are other options. You can enable using her head as a switch in the iPhone accessibility settings.
The Jelly Bean looks good, thanks. There are lots of rabbit holes to fall down (and that can be helpful) but I’m finding that I need a bit of vocabulary first before I can even google effectively. Thanks to all who are helping.