Y'know, my guess is that she wanted him to.
She'd probably have smacked up at some point in the not too distant future even if Doherty wasn't there to do it for her. Granted, he may well be doing it for her because it's her first time and she doesn't know how to, so she may well be throwing her life away for junk from here on, but someone else would've done it for her eventually.
Or, perhaps, like Pete, she's a smackhead who asked him to do it because she was too out of it to do it herself.
I dunno, junkies will be junkies. People who force drugs on other people are *****. But I don't think that's what he did. She asked, I'm sure. It's a shame people do that to themselves, but printing it in The Sun won't change that, nor will painting Pete as an evil person. Far worse are the people who keep girls working as sex slaves through forced opiate addiction. But cases like this overshadow that, unfortunately.