Katie, Nursing experience isn't as impotant to airlines these days as it once was.....& I think I'm right in saying that unless you keep your nursing qualifications fully current you can't actually give any more care than your cabin crew training allows. With more & more airlines carrying automated defibrillators & using the satelite telemedicine services nursing experience is becoming much more of a "nice to have". My airline's procedures have us call the satellite telemedicine service way before we start finding out if we have a doctor/nurse on board....they know exactly what we have in the way of facilities/equipment/drugs on board, wheras your local GP on his hols may not be familiar with the particularities of treating a patient in the air, in fact they are not allowed to touch our defibrillators as they are so different to what you would find in your local A&E.
There are loads of cabin crew flying who have been through further education & in this day & age it is important to have something to fall back on. Whilst I was at Uni I spent the summers working for Air France at LHR in T2 as a Customer Services Agent (checkin/boarding/meeting flights) & found the experience worthwhile. Might be worth checking out at your local airport who the handling agents/self handling airlines are as most of them will take on seasonal and/or part time staff....I know Aviance at LGW take part timers on working 18 hours a week.......this kind of work certainly gives you a good grounding in the operations & customer service side of things.......invaluable for a cabin crew job. Good luck!