She is you Phupo, Your Dad’s Sister. And I’m guessing you dad must have high regards for her for some reason. Try and look into that.
Why is she jealous of you? Is she just a jealous person by nature or there is something in you guys behavior that drives that from her? Think Deeply.
No matter what, the bottom line is that she is your phupo and it won’t kill you or your ego if you go and meet her up. Think about it! It will only make your dad happy and you a bigger person by forgetting whatever negative feelings she might have given you.
Always try and rise above situations. I know its easy said than done but atleast in family matters one should never involve ego. Family is the most important thing in life so value it and cherish it before its too late for that.