I have mixed feelings on this.
I would never want to hurt my org, but I would think that maybe this would help her like others have said maybe it is her self-esteem.
But then again maybe it isnt true at all. Have you talked to your friend about your conserns? I mean after all she is your friend. Then maybe when you have talked you may discover a new truth and there will no longer be an issue of bringing it up to your sisters.
Just my opinion...