This might not help, but there was an old bug that could prevent sharty’s romance scene in act 3 from triggering. You’d have a conversation in the morning as if it had, but you wouldn’t see it.
The solution to that was to go back to a save before that night, kill her, resurrect her and rest.
Super minor spoiler:
I actually failed to kill her and picked up an inspiration on the first attempt. After she hurled herself off the bridge into the water, she just reappeared back at camp having learned to swim (or something) . Second attempt I made sure she was dashed on sharp rocks. Ouch.
I don’t know about not being able to give her the orchid. I don’t think it’s required for the romance though.
Might be worth a shot?