Firstly I’d follow up what has already been said about fit is king. A good fitting suit will probably feel a lot tighter than she is expecting if she has not had one before – you really don’t want pockets for water (usual is small of the back). Flexibility is also so important especially in the shoulders. Putting one on properly is not actually that obvious either. It might be best to go somewhere if possible for the first one.
My wife and I have relatively new cheaper suits after years of much higher quality (BS helix). Mine was cheapish (circa £160) and my wife’s v cheap (circa £100). We got them because we are currently slightly too ‘comfortably built’ for our old suits! Got to say they are crap, especially my wife’s blue seventy sprint. If that was your only experience of a swimming wetsuit you might not know any better but so inflexible and the the reduction in the number of panels means it would never fit particularly well. My wife also struggles with too much buoyancy in the legs in cheaper ‘beginner’ suits trashing her stroke. But they do a job for two folk that don’t race anymore…..
Or do they!?! Just back from your neck of the woods and swam at least twice a day without a suit – skins for the win! Our suits tend to travel with us but don’t get used. Swimming mostly in fresh water lochs lat week in 9-10.5 deg water (colder than the sea) and it’s fine. Once you manage the first 6 minutes it’s all good. Even my 70 year old mother was swimming with us skins (out of choice, she has a wetsuit too) and it’s so much more pleasant. I don’t want to go all new age hippy but there is a connection with your surroundings swimming skins you don’t get suited up. 4 of us did a new moon moonlit swim to the middle of the loch being buzzed by bats which was epic. Add a pair of neoprene gloves, socks and hat for when it’s a bit nippier to prolong the experience. I tend not to be in for more than 45-60 mins at that temperature and a suit would extend that but unless specifically training I’d rather manage without these days.