Somnambula: Jinn knew so many things given how long she lived, it’s hard to recall everything she did. But if I had to say something in particular she was good at, it was definitely any wishes that had to do anything with her talents prior to being genified. That being botany and geology.
Though that doesn’t mean like poofing food out of thin air normally grown through plants actually tasted good when she tried it. She still had to farm it like any other pony if she wanted it to taste good. She was good however at using genie magic to assist the growth even in conditions often unsuitable for plant growth. In that way she found somewhat of a loophole at least with naturally grown foods. They still had to wait for it to grow, but otherwise Jinn managed to simulate the required amount of sunlight and water to help fruits and vegetables grow even in the coldest of winters or the harshest desert heat.
I imagine initially it was used to help Saddle Arabia during the really hot summers. But I was there once when she helped a village which was suffering from an abnormally long winter. I could see the hope in the villager’s eyes when she did that!