I took it when I was in my early twenties and it was fantastic. Yes, it does dry your skin but when you've put up with acne for years this is nothing to worry about.
I have suffered again with acne now in my 30's, . BUT, I have now been prescribed some different anti-biotics, trimethoprim, and the results are amazing!! I have had anti-biotics before with no change whatsoever, I thought I would have to go through the whole timewasting process before I could get to see the NHS dermatologist for roaccurane, but these have completely done the trick. I have had 1 tiny spot since I went on them about 4 months ago, so it shows that, like a lot of illnesses, it is not a case of one type of antibiotic treats all, you have to sometimes try several before you find the right one.
If your friend's daughter hasn't tried more than 1 or 2 anti-biotics then maybe try some more first.
As for the side effects, yes, they do sound bad but I would be very interested to know how common they are. They always get a lot of publicity but I think most effective medications have nasty side-effects, it just depends how common or rare they are.
I think people who don't suffer from acne don't realise how it wrecks your self-confidence and self-esteem.