Being under the thumb of part of my past at this place unfortunately excludes me from sharing all personal experiences as I once felt free to do, but if I had to wager, I think fast forwarding a few years might find you and her in a frank discussion with absolutely no reduction in your amount of fondness, although changes in age can have a completely separate effect. You don't like to ponder what others who speak from personal experience have to offer, so I'm willing to have you blow the dust off this post in a few years (search doesn't work. Archive site, perhaps?) and see if I was guessing correctly.
Another prediction is, provided you keep distance, I know her parents won't do anything serious or legal, since you say there were no legal boundaries crossed, and because your relative sounds like she has a good head on her shoulders anyway.
From personal experiences, try not to dwell longer than it takes for the parking meter to run out. There are always new experiences waiting.