SOLVED. Book about meth with a girl called gem [s]

[Matthew]

I think its about a girl called gem and her boyfriend, they run away because the guys dad is hitting him, they "squat" in houses for awhile, they get hooked on meth, gem gets preg and they try quitting.

Set in England semi modern day.
Intended age range is YA

[Lobstergirl, au gratin]

Junk? It's set in England and one of the MC is named Gemma, but it's heroin, not meth.

[Matthew]

Yes! thank you so much