Flaky artex paint on Velux window void

[terreetee]

I'd appreciate some advice as I can't afford a professional do this job. I've scraped the flaky paint back and it's back to bare plasterboard in parts on the Velux window void in the bathroom.
I was thinking of a PVA mix and then start applying paint. Would this be an appropriate way forward considering some moisture does blow in during wet and windy days?
TIA

 

[opps]

PVA re-emulsifies when damp.

I can't see what the problem is from your photo.

It might be prudent to apply dilute emulsion to the bare areas and then use waterbased eggshell to coat the whole area. Any moisture will run down rather than permeate the emulsion.

 

[Wayners]

Condensation problem that will always give trouble there. Plastic cladding maybe an option...
Pvcu White Interior Cladding