Yes sounds like a typical spoilt 'mare' to me. You will never fix her attitude problem for good, she will always resist, and this will make it hard to train her in the future. You can approve her 'listening skills' but I don't believe you will change her 100%. Parelli may help, I have seen it work wonders and I have also seen the negitive affect. I wouldnt do much lunging with her, like most young horses, there mind is off the job, and many can not concentrate.
At this stage I would be taking it slow. When is your friend thinking about breaking her in?
Hope I was some help