Where can I find a npc that sells destruction SKILLS?. I know that in the winterhold college there was a NPC female but I can′t seem to find her anymore...

Edited

Each of the Jarl's palaces have a mage that will sell you spells.

I think the Riverwood Trader sold some spell tomes, so you might want to try looking in some of the shops as well.

I'm not sure, but I am sure that Google knows, that someone has already asked this, and that UESP (Skyrim wiki) will know.

Ermmm, I misspelled. What I′m looking for is skill seller, not spells.

Mmmm I think I know whats the problem.. I think the NPC is named Nirya but for some reason she won′t sell skills anymore.. the only dialogue im able to interact with her is about a problem with Faralda.. Anybody can trade with Nirya? or it′s just me?

No, it's not Nirya. It's Faralda who is the Destruction mage.