How long have you been growing your girls?
Based on the pics, there is a lot of new growth.
From my experience, gnats won’t hurt your plants just a nuisance. Jept a bowl of water in my tent fr humidity & found most of the gnats died in the bowl. Maybe something’s ng to try.
I agree with @Smokin_ernie
, that your girls look dry.
Here is a chart to help aonowledge possible problems based on your leaves.