Looking for a bit of advice. I'll make the background as concise as I can.
I had a massive falling out with a girl I was crazy about back in summer 2009. We were at uni at the time doing our vocational training for the particular profession in which we work. We were close and I felt a real connection to her. However, I'm quite reserved and thus I never got the chance to ask her out and declare my interest since she began dating another guy from the course that I'd taken a dislike to anyway. Basically, I expressed my feelings about the situation in a completely unacceptable manner and the rift between us was, at first, completely unspoken. I didn't even have the balls to apologise. I cut off all contact and we didn't speak for months. I thought I'd just move on, curse myself for my actions and leave her alone as she was bound to hate me.
She confronted me a few months later and it turned out she didn't hate me. In fact she asked me not to hate her, something that had never been the case as far as I was concerned. She informed me that, but for my actions and the fact that she was with someone else, we really might have had something. She said all this while holding back tears. I kind of wish she'd never told me this. All my feelings came flooding back and my timid attempts from that point on to at least reach some sort of reconciliation stalled, mainly by her own loyalty to the current boyfriend who had been the primary target of my ire. However, only months after her confronting me did she delete me from Facebook, an unremarkable event in itself. I can't say I was too bothered. I was surprised she hadn't done it sooner.
Anyway, last April I saw her at a social event and at the end of the evening she approached me once again. We had a rather emotional 5 minutes where I managed to hold her in my arms and whisper to her how unbelievably sorry I was, how she was the last person on earth I would ever want to hurt and she was the only thing I'd thought about over the last 5 months. She apologised for deleting me (as I say, it wasn't a big deal for me). She strongly inferred it was on her boyfriend's direction. I told her there was no need for her to explain herself to me. We were grasping each other's hands as she left, saying we'd chat soon etc. I felt on top of the world for the next 3 days not because I had made any progress with her per se, rather it was the relief of getting many feelings off my chest.
I probably should have left it, but I texted her a couple of days later wishing her a happy Easter and expressing my relief that we'd been able to talk finally. She replied almost instantly, referring (again) to the Facebook thing and implying (again) that it wasn't her decision. She said the boyfriend was still angry at me and that any contact between us was therefore inappropriate. She then went to great lengths to point out that this is not how she would want it in an ideal world. I replied simply, saying that I'd meant everything I said to her but I respected her judgement.
I've seen her twice since April in official circumstances and in the presence of her boyfriend, who also works in the same field. On both occasions seeing her hit me very hard. I so wanted to talk to her but I had to respect her wishes.
My question therefore is should I contact her? I have her number but I don't want to do anything as immediate as sending a text message or, worse still, calling her. I'm 99% certain of her personal e-mail address but I know her work e-mail for definite. I would only be sending a brief, friendly message. I may have spent the last 18 months thinking about her but she doesn't know that. I've made no attempt to initiate contact since April and on the last two occasions we've spoken face to face, she has been the instigator. I don't want to be a stranger.