i really want her fur trimmed coat (i already have the noble clothes) and she essential is there a quest or something i have to do or is she essential for good? Thanks!

There's always a way if you're on PC...

But on consoles, no.

Isn't it possible to steal equipped items if you have a high enough level of pickpocket?

Apparently, there is.

http://www.gamefaqs.com/boards/615803-the-elder-scrolls-v-skyrim/61148400

I have yet to try it, but i will give it a shot, even tho my craptop can't run Skyrim properly, it can still load it up...

You just cant put any items that are not in the vanilla game on your save like mods ect, only things that are in the base game~