Thanks guys. I'll have to check those out. I also found
Somewhere in Time by Rachel Young. Charles is the son of the knight hired to protect Tempos's parents (they are some kind of "lord" but it is undefined) with Charles to protect Tempos. Tempos's parents have entered into an agreement with Loisette's mother, Ellen, to have Tempos and Loisette marry (without Loisette's consent), because the Lanes are wealthy and Tempos's family lives beyond their means. It is supposed to have a sequel named The Reunited, but I couldn't find it. She must not have ever submitted it to the Archives (if it was ever completed).
