Rhonda
It is part of a series where the oldest, the laird, doesn't want to be in a relationship until all of his siblings are "settled". I think it was a promise he made to his father.
Andrew Franke
Have you looked at any of the "Murray"Novels from Hannah Howell it seems to me from memory, I have read all of them, that a couple might be part of this Family series you have been looking for.
Rhonda
I read it maybe 4 years ago. For some reason she was at his castle and they had a bickering back and forth. Hers was because of rejection his to keep her away. The siblings started to see it and "helped". I know this is kind of generic being that is the plot for a lot of these books, but I can't remember anything else.