Theoretically you could go to an E start on the XR2, but it's not easy -- or cheap.
In Japan, they have the XR200 with electric start - it's a dual sport bike called the SL200.
You'd have to purchase the cases, starter, wiring harness & ignition system. The starter is run off the crank, so you'd probably have to get a crank assembly also.
Is it worth it?
If the XR is hard to start, try adjusting the valves. That might do the trick. If it's an easy starter, but just more than she wants to deal with, look for a used Yamaha Serow or XT225. About the same HP, disk brake, and electric start!
BTW, although BBR are the chassis guru's - they don't really like working on engines - especially stock stuff. Don't hound them with questions like this - it's not their specialization.
If you're looking for the guys who know about four stroke engines, check with Powroll, they're the ones who have provided BBR with many of their go-fast engines and parts over the years.