Mutation,is it genetics or something else?

Yeah it can be genetics. This run i got a Jelly Donutz by Humboldt comp. with 3 leave sets. My friend got an OG Kush auto by fastbuds, also 3 leave sets. Both from seed. This looks even weirder, but let it grow. I would not care about it, as long as the later leaves seem normal. And the newest one already grows normal. The rolled up edges make me think it's maybe a little too hot for them as seedlings. 28°C with 60% RH is ok for later plants, but the seedlings struggle. You even have to water them way too much with this heat, looking at how much you gave her.