Most Helpful Girl
Wow. It seems like you have pretty good judgment of the situation. You realize that she's "rebounding", that she's not exactly in the right state to be making terribly sound decisions.
I'd say she's interested, but like you said, she's not in the right state. I would suggest to do what you're already doing; wait a little longer so as to allow her feelings to level. You can still be there for her because it seems like she is looking to you for comfort, but don't get caught up in rushing things along just because she's flirting with you/feeling you up/etc. And, you also noted, her mood is still fluctuating (really flirty one day, not as interested the next day), so that's a pretty good indicator that she's not fully over the other guy yet.
Most Helpful Guy
It's hard to tell if she actually likes you as anything more than a friend. Yes, she was flirting, but she's most likely just looking for a rebound. If you really like her, I say wait it out until she's over her ex.