Romance. Hero and heroine have a secret relationship when she is in high school. They make plans to leave together, but hero leaves her behind so she can have a better future. They get there HEA after 20 years

[Shelia]

I need help finding a book. I thought it may have been one of Elizabeth Kelly or Elizabeth Lennox books but not sure. I don't remember much just this.

I believe the hero and heroine are in high school maybe. Hero works at a mechanic shop ( not 100% sure but owner of shop may be hero's uncle) and live above it on in a place behind it. Don't remember much about Heroine. I believe heroine was rich, popular or something and hero was as they say lived on the wrong side of the tracks, I also believe they may have kept there relationship secret of that reason. I believe they wanted to go away together but hero ended up leaving without telling her, but left a letter for her with the guy he worked for. Years later (I want to say it was like maybe 20 years later) they end up running into each other or something. They both have kids and later end up getting married. Hope this helps TIA

P.S
Not a 100% sure but I believe heroine's father may have been behind the hero leaving somehow. I think he talked to him saying if you love her leave (I think she decided not to go to college or something).

[Lobstergirl, au gratin]

Is this a book that is on your Goodreads shelves?