An old crush recently popped up on Hinge. What should I do next?

I met Sarah through my then-best friend as she was his sister. We all went to the same school and she was the year below.

I’d seen her around a few times at their house but it was only when she started at upper school that I developed a serious crush on her. At that time, I was always too afraid to say anything in case it had a negative impact on my friendship with her brother or made anything awkward.

However, looking back I can’t help but feel that maybe she might have liked me at the time. She gave me certain looks whenever she walked past me, smiled widely at me, gestured to me on a couple of occasions and even one time, we were sat opposite each other in the library on the computers. All of a sudden, she and her friend logged off and then she came round the other side and sat right next to me, although we didn’t say anything to each other because I was too nervous. I’ve never had closure on this and I regret never trying to make a move at the time. I still wonder if maybe something could have developed back then?

Years later, when we were both at uni, I finally plucked up the courage to message her to ask to meet up but she awkwardly replied without even acknowledging the question. Months later, I saw she had a boyfriend, so that was that. If there had ever been anything there before, she’d now clearly moved on.

Fast forward to a few months ago, her brother is no longer on the scene (long story) and I find out from my mum that Sarah went up to speak to her at a salsa class they both went to and that she’d come with a male friend (presumably that or another boyfriend) so it was nice that she’d approached my mum like that, considering she'd never really spoken to her before, but I tried not to think too much into it because it looked like she was still with someone.

However, a few days ago, I was scrolling through my Hinge and she popped up! Obviously, it now looks like she’s single again. I sent a rose and a short message saying hi but nothing has happened. I assume this means a non-match, but I suppose she could also just not use the app much? Nevertheless, I feel maybe I should message her on social media again (we’re still friends on FB, we follow each other on Insta) just to try something one last time, but what do I say and how can I say it? Should I ask to meet up and what could I suggest? Should I also throw in a get-out clause, such as "completely understand if you don't want to" etc.?

I'll also just point out that I haven’t seen her now for about seven years.