I think nothing is more humiliating than keeping you reminded by someone of the act of kindness that he or she once offered to you, no matter how long it has been and how much effort you are giving in an attempt to reciprocate or return the favor.
I scratched your back so how dare you not to scratch mine?
Maybe because I have grown my nails so strong and sharp and scratching your back would be fatal.
Yes, you should be grateful because she helped you get a job nine years ago. But then you have worked hard all these years which made you establish your name and value in the company. You should owe your success to your self by this time. And if I'm the person that gave you the employment opportunity, I would feel somehow repaid by just seeing you advancing in your career.
Unfortunately, the actual grantor doesn't feel nor see it that way. She's too numb to notice it. Too bad, my friend.