How would you feel...?

A family member with whom you've had an extremely contentious relationship with for many years and who is still a pain in your backside, lets it slip out in conversation that she's held a grudge against you over something that happened 25 years ago. You suspected this all along, though she denied it several years ago when you asked her straight out if she was holding a grudge. What are your thoughts on this and how would you feel to know that, basically, everything that's transpired between the two of you over the past 25 years is in the context of someone who still holds a grudge?