I would go direct here. Like to her initial answer of "I don't want to date" you could have simply just replied "Why is that"

I've sent out two of these types of messages the past couple of weeks in similar spots to yours where I got left on read. One worked, one didn't. Again I'd suggest finding his videos on this topic and watching them as it is pretty nuanced. Also feel free to play around with all of this wordage to your specific case. The one girl I had actually hooked up with a few times, so I made my message more sincere. The other girl was a bumble date who I never met, so I shortened it up a bit and made it more to the point.

Basically something like "Hey her name I saw xyz callback something specific to your convos and thought of you. Honestly just curious at this point, is there a reason you weren't looking to date? We had a good vibe that night, I wasn't asking you to marry me, but it would have been cool to get to know each other more over a coffee/drink. No hard feelings, just wondering. Hope your spring break went well"

I think most guys just give up here. But you'd be surprised. Sometimes just giving it a few weeks and coming back cool, calm and collected is all you need. If she had any interest at all in you, you should at least get a response back.