Betta Fish: Female betta stress stripes

I've got myself a beautiful little betta imbellis girl who's been with me about a month. I'm pretty certain the tank lights are causing her some stress, as she tends to stripe up when they're at their brightest. Trouble is, I'm running a planted tank. Currently the lights are at their brightest from noon to 4pm, when they start dimming to a more comfortable level for her. Will this cause any longterm issues? Should I cut back on lighting?

The first two photos are of her when the tank lights are dimmer, the last shot is of her with her stress stripes on display.

Tank is 7g, lots of live plants (other half of the tank taken over by red root floaters), driftwood, and hides. Filter yes, heater no (live in tropical country), water parameters tested at my LFS 0, 0, .5. She also rooms with three oto catfish whom she loves to sleep and school with, alongside amano shrimp and misc snails. 30% weekly water changes.

Thanks!