Gourami acting weird?

[Annastasia]

I recently moved my blue dwarf gourami into a newer tank. She has always been a timid fish,hiding under ornaments, in plants.... A couple of days ago, she started hanging out near the top of the tank. Is she becoming less timid or is something wrong?
All the other fish in the tank are acting normal. Please help if you can!

 

[Colisa lalia]

Is she hanging at the surface gasping or swimming around with jerky movements?

 

[Annastasia]

Nope. She just sits at the top. All the tank conditions are normal, too.

 

[Inchworm]

Hi Annastasia

Gouramis are fish that normally do hang out in the top level of the tank. They might not stay there all the time, but that's their territory.

 

[Annastasia]

Thanks for your help with that. I have another question though. (sorry!)
My same gourami, whose name is Jewel, has a brown spot on her tail. It doesn't seem to be affecting her, but it is getting bigger.

What is this?
And, is there anything I can do to treat this?

Thanks!

Edit: Avatar. Ignore!