Looks like one of three possible reasons to me. Nitrogen burn, light stress or you overwatered her a little bit, all will cause yellow tips. Your leaves are curling up towards the light so if you haven’t had any water issues and you’re not trying too supercharge her with nutrients, I’d suggest raising the lights a couple of inches and see how that effects her. I would also suggest letting her dry out a bit and water her good with some fresh ph’d H2O.
Happy gardening!