It turns out that my interviewer is my old friend's mom, what should I do?

Turns out that my interviewer for Penn is my friend’s mom. She doesn’t know me directly, I never met her (although I was her Facebook friend when I had Facebook) but I was close friends with her son last year and not sure whether this would make anything awkward.
Should I tell her about this? Should I request to change interviewer for this reason? (Also this is a Skype interview and I always prefer face to face interviews so maybe I can tell her this too?)
I need to email her back today, someone please help me answer this!

As a former interviewer at a HYP, I’ve had a situation very similar to yours. I informed the regional interview coordinator of this conflict of interest and switched the interview with someone else. You should do the same.