Jaheira's romance and Harper Hold quest are different thing, and the latter one can be done without having a romance with her. To get the pin you must have a good REP, some 17 or higher. Anything below that will not yield the pin and the quest is considered as "failed".
As for Jaheira herself, then she's pretty OK. I like to have her in the party and the romance is also pretty well done. Good work, not to mention that she's definately a pretty useful party member.
__________________
|