I managed to give both parts as a gift, the first one I gave triggered a quest update, something like I successfully gave one of the map parts. When I gave her the second part nothing happened, she just accepted the gifts and now the quest just says "Give the clue pieces to Zarah" and nothing happens when I talk to her.
#zarah's fabled treasure
quaint shell
grizzled obsidian
you may or may not have bricked that quest. you’re suppose to bring the two pieces to the docks near her boat. maybe try digging in the ocean and in the mines to spawn the parchments again? I hope that helps somewhat!
they need to make it so that you can’t gift them to her in future updates 
dusk solar
I heard someone else’s quest broke because of this. You had to take them back to her house per the instructions. I genuinely don’t thinks theres a fix right now, maybe you could try and back up your save? But that’s the only you would be able to do so
desert laurel
I was hoping for a workaround too, because I'm in the same predicament. 😭