don't see why not. Specialized makes a MTB shoe that's about $50 give or take that is very comfortable as a walking shoe. I Think the cleats actually come with the pedals so she wouldn't have cleats to deal with until she buys her pedals. But either way - just don't install the cleats until she has the pedals.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"