OP my last point is... the drunken 'Benidorm' reputation is only from the Brits.
I presume she'd be with these same Brits drinking in the UK?
Spanish teenagers are so much less into alcohol and much more into sport. The difference is eye opening. They don't really go to bars. Only for coffee or fanta.
Benidorm is beautiful with a few fish and chip type pubs (I actually went to one so DD could have proper English chips with malt vinegar)
And the boozy 'strip' with tourists and stag do's/hen do's are, who can't get over how cheap booze is and do a pub crawl.
The only reason they went 
and one that is giving this reputation.
They also have 'tapas alley' which is absolutely amazing! Seriously incredible little stand up bars with delicious tapas. You just have a small beer (tiny, like half a half) and a lovely tapa, and on you go...
Great fun.
The old town and bit between the only thing you need to worry about are about a million waffle selling places. The smell of sweet waffles was a bit much. Good shops, Zara, Mango etc and Tiger, which is where I had to go for squashies/squishes or something!
They were charming in the English bar, really lovely and DD loved it.
I want to go now! I honestly am going to look at at few nights at Easter I think 
The beach is a blue flag awarded European beach, it is incredible. So clean!
Last thing... beginning of July will really not have as many tourists. Mid August will be heaving!