<human>: I'm 28M, she's 21F. This is already a bad idea. 

I've known her for quite a long time - one of those things where you're in your early 20's, and you're hanging out with someone a bit younger who brings their friend who's a bit younger than that and he brings his girlfriend who's younger still, and pretty soon you've got a 7-year age gap in the room.

We've stayed friends over the years - I usually saw her at least once every year or so, even after we stopped hanging out in the same circles.

Anyway, I'm fresh out of a long-term relationship (red flag on me!), and I've been becoming fairly close to her. There's never been any "interest" between us, but it seems to be developing now. We've been talking online a lot (which is sort of silly, because she lives within walking distance), and hanging out a bit. 

Here's the problem. Other than the age difference, there are about a million red flags about this chick. She's been doing hard drugs on and off since she was a teenager, she's emotionally unstable to the point of low-grade self-harm, and she lives at home. Also, she's a bit of a SAP (feels self-conscious ordering at bars, etc.) and none of my friends can stand her. The last is the biggest red flag; my friends are more important than any relationship to me (maybe that's another red flag on me, but that's how it is). 

The reason I'm entertaining all of this is that over the last few months, she's really made tremendous progress in turning her life around. She's gotten out of an unhealthy relationship, gone back to school, mended bridges with her family, and she seems generally serious about self-improvement. I'm also at a point in my life where I'm trying to grow as a person, so we have that in common.

To cap it all off, she's ridiculously hot.

My question: is there any possible way hooking up with this girl could end well?

Provide a brief overview of the text.
<bot>: I have a crush on a girl who's much younger and probably very bad for me, but she's trying to become better. Can I pursue this without it exploding in my face?