While I'll admit I'm not an expert with hounds- having Wire Fox Terriers- this kind of behavior is quite common in Terriers- esp. Female terriers. In our kennel we rarely can have 2 females at the same time in the house w/o a fight breaking out. In my kennel- I have only 1 female that will get along with anyother dog/female in the kennel and she is the expception beleive me! Her daughter is somewhat like that too- but she is still young (at 7mos)
Part of your answer is in your post: you say she was never socailized- so she is not used to having other dogs around and having to vie for attention. IMO this maybe a long road - or next to impossible to cure entirely. You don't say how long you've had her. I would try seperating her from the other dogs as a start- put up some baby gates so she has "space" and the other dogs have "space" let them sniff/ see each other but have no direct contact. Continue to talk,praise, play with her- but seperate from the others. Then with her on a leash- (after maybe a few weeks of this seperation) have another family member walk her into a room with the other dogs- give all of them attention- if she starts to fight with the others because they are getting attention- tell her NO-Stop! - and make get into a sit position. Keep her on the leash. Then pet/talk to the others again (and her too) This should help her realize that ALL will get attention - but that she cannot get aggressive to get it! Has she been spayed? How about the others? This may help somewhat -
I know some of the other ladies on this list will have other suggestions- there is a "nothing in life is free" method- this maybe what she needs too. While not impossilble to get a 5yr old dog to accept others if she truly was never properly socialized (this takes place initally at around 6wks-8wks of age) she may never be able to be 100% comfortable with other dogs.
Kathy