Welcome I would say it's way to hot in there and to me looks abit over waterd let it dry rite out and water small as she's still small and are you watering the hole pot or just around the seedling?
Ur.not.using garden soil are u.looks.like.the soil is compacted to.hard not enough. O2 can get to the roots csueeing slow.growth.loosein the soil with a fork around her don't water on her water 3-4 inch's away from her so her roots have to.reach out