I am new to the site and did not know where to post this so here it goes!
I have a quaker parakeet who has recently started to mutilate herself, so i am going to get her a companion bird!
A prince of whales, or a ringneck.
What do y’all think?

If you intend the birds to be friends and perhaps allopreen, then neither princess of wales nor indian ringnecked parakeets are suitable.  A small conure, another quaker or a rainbow lorikeet would be more appropriate buddies but be careful as introducing a new bird into a stable home must be done slowly with good advice and a shop that will help you.    

Thanks for your advice… But why would my vet tel me those birds ar suitable…. I was going to go with a sun conure but they are just to beefy! oh well thanks thought appreciate it!

Ruthie,
The birds you mentioned are fine to have in the same room, but they do not preen one another under most circumstances. Whereas Quaker Parakeets are very touchy feely kind of parrot. Personally we have mixed quakers with all the ones I mentioned….another very good choice would be a Green Cheeked or Maroon Bellied Conure as they are not too noisy (quakers can be sometimes) and are affectionate. Getting an opposite gender bird—- if yours is a hen, then a male would suffice—-is a good way to go. They may get a bit sexual if they learn to like each other, but that is usually easily dealt with in a home.  The need for counsel comes in in the way one goes about introducing the two parrots.

Hi Ruthie,
If I was you I would try to find out why your parrot is mutilating first. Introducing another bird may be more difficult of what you think if your bird has got problems, mine is not accepting any other bird for example and he is perfectly fine with people and healty. I have known of birds that were mutilating themselves that tried to mutilate birds that were with them! You may end up with two plucked parrots that do not like each other! I would have a word with a good avian vet and I would consider to find the problem (diet or may be boredom?!) to start with and than see what happens.
Good luck
Anita