It is a solo only quest. You might want to check out this thread;

http://forums.elderscrollsonline.com/discussion/64996/fighters-guild-first-boss-lady-impossible-to-kill-solo/p1

Here is another long one;

http://forums.elderscrollsonline.com/discussion/63953/the-difficulty-is-insane/p1

It also depends on what faction you are in. With the Dominion it gives you a big room and I was able to defeat her pretty easily with my bow-nightblade, but with the Pact it is a confined room that gave me lots of trouble with my sorc

I must confess that I am having the same problem, and the number one culprit for my problems can be pegged on one thing. The collision detection. At some point in the fight her body is going to block me from getting at one of the orbs, and that sends me right back to square one.

Basically it is too big of a body in too confined a space. Making matters worse if you are primarily a ranged attacker. It does take more then a single strike to do in the orbs. So while you may eventually succeed with some luck. It is actually punitively expensive to do so.

The obvious solution would be for the developers to tether her to the chamber just prior to her room. So ranged combatants can have a encounter that is more skill rather then luck. I can see where tanks, and healers can have a much easier time with it, because they can stand there and take the pasting, but for the hit and run types it is basically suicidal.

For a Sorc... the Storm Atronach helps.

Came at this with a new character. Either templar is way easier than sorc or maybe Im just a better templar than sorc. Beat it at level 8 when the sorc couldnt get it at 11. Didnt even have silver bolts, though to be fair to the sorc he didnt either.

With my lvl 10 sorcerer , i died once because i got stuck on a floor tile , but after i revived i , had no problems with her , i used Overload to beat on her and the orbs at the same time , in a small room , since the DC has an enclosed space as well.
The AOE from that ultimate and the fact that it was a toggle helped me out a lot , basically couple Overload with Lightning form and you don't even feel her attacks :P

Dragonknight here, couldn't do it at 8, or 9. Tried it at 10 after I got my first ultimate (the Dragonknight Standard from Ardent Flame). Eventually got her at 10.

The fight is problematic at a few points, and I bugged these, but figured I'd share as people are having similar problems.

The orbs spawn relative to the room she's in. If you pull her out of her spawn room, the orbs travel a much longer distance to reach her, giving you more time. The issue is that you can't draw her too far, or she leashes and returns.

Fighting her in her own room, you have to have the DPS to burn her down between orb spawns, or it's just not gonna happen. Sure, you can plan from level 3-8 and spend every skill point just preparing for that fight, but honestly, that's broken design, and I'm sure Bethesda knows that.

In my opinion, in fully crafted gear, with an 'average' set of skills, the easiest way to deal with the fight is to outlevel it and return at 10 or 11. Once I was able to drop my Ultimate, Dark Talons, and use Brawler on the orbs, it eventually did work. But it wasn't an easy fight by any means. I had to try it a few times to get the timing right, and the orbs are buggy as hell.

Adjustments to make the encounter reasonable?
Have each orb heal her by a small percentage, perhaps 5% per orb, so that she doesn't heal up to full so quickly.
OR
Reduce the number of orbs, such that she can't heal more than 25% per cycle.
OR
Reduce the hit points in the orbs, so they are destroyed by -any- damage.

So far, up to level 12, Doshia was BY FAR the most difficult encounter. Gutripper was a dream compared to Doshia. The Wyrd Tree corruption fight was a walk in the park compared to that Doshia.

That's my opinion, enjoy the game!

i just CC nuked it down with my lvl 9 nightblade lol only died at the 1st try.....

Just make it so you can bring a friend along to help you out. It is an MMO for god sakes and why do MMO developers think it is a good idea to make single player ONLY quests in MMO's?

Anyway I see in the latest patch they have nerfed Doshia's abilities so it should be a cake walk now...which is the WORST solution they can possibly come up with because pretty soon you can solo the entire PvE content and then the game becomes nothing but a boring grind.

Not to mention that when you destroy the orbs, they heal you back instead of her. I did it with sword and board DK. And you really should interrupt her big attack, even though it won't stun her, at least she won't suck your soul out.

yeah just wait till higher level

Wow if you cant beat that easy boss Doshia, then R.I.P when you get to Lyris' Doppelganger at level 30