My DG is sick! Help me

Ok so I have a pair of dwarf gouramis and the female is showing signs of illness. All water parameters are normal. I brought four new guppies home last week, but apart from that nothing is different to normal. It looks as if the scales around her gills are either gone or irritated, raw looking and pink. She’s at the bottom of the tank hiding in the leaves most of the time and isn’t eating normally. I’ll try and post a picture of her. PLEASE HELP ME!

Dwarf gouramis are notorious carriers of DGD, known as iridovirus. No cure for it, you can separate her and see what happens next.
@Colin_T

What are your exact reading for the water?

Water reading would be useful, did the guppies so any unusual signs of illness, as @Salty&Onion stated if it is DGD there is nothing to be done and that seems to be more and more common with them.

Other possibilities for red gills can be from ammonia or chlorine or unclean water. When did you last do a water change and by how much.

You didn't quarantine the new fish and this is what happens. The guppies brought in a bacterial infection that is killing the gourami.

You can try 2 heaped tablespoons of rock salt per 20 litres of water. Keep the salt in there for 2 weeks.

Or you can try a broad spectrum fish medication that treats fungus, bacteria and protozoan infections.

There's no guarantee either treatment will work.