Looks like 'rose dawn' to me. it is one of the last to finish flowering here.

I even notice the same fine serrations on the leaves.

Looks pretty. Reminds me of Julia Pink and Lady Clare but the shade of pink may be off. LC is a late bloomer too; don't know about Julia. Stop by the school and research with whomever minds the landscape to see if you can either find out or get cuttings. Based on the size, it must be several decades old and it likes that spot.

Thanks! I've never heard of Rose Dawn, but that's really, really close. I'm sure there are a million varieties that look like this. Rose Dawn looks to be a zone 7 variety. I would have thought this plant would be a hardier variety, but you never know. It's in a near-perfect siting for this climate.

Luis, not familiar with Julia Pink. Lady Clare is offered around here. Ones I've seen have larger flowers and perhaps a more obvious boss of yellow stamens.