Hello everyone. My girlfriend recently had to have major surgery on her spine in which she lost a lot of sensation on her lower right leg.  She has developed Complex Regional Pain Syndrome in that leg, which means she has occasional pain flareups.  We have a bunch of trails around where we live and live in a relatively bike-friendly city, so I want her to be able to ride with me because keeping her legs moving helps with the blood flow.  I am looking for a bike that is very stable as she has trouble with balancing and has a weak right leg.  Should I be looking for a fat bike, a trike, or maybe some other type of bike?