Assuming the person (Male or female) is physically able to complete the job with out hurting them selves I think they should know how to and be willing to the change a tire.
Maybe I am mean but when I met my wife I taught her how to fix the car (Motor repairs/lube/oil/tires/exhaust). The reason is I believe every driver should know car basics so you know if the Mechanic is telling the truth. Also do you want to be stuck on the side of the road because you do not know righty tighty and lefty loosy?
Diplomatic answer Krakyn but you're right. Still, nice to have a strong man do it, that's what some men don't realize, its that we don't know how its that we don't want to do man's work.