SWOT
You could put her on the spot and say "what do you mean by that"?
She sounds passive/aggressive to me.
It's like an insult inside of a compliment in a way.
My sister in law who is 70 has talked so badly about her husband and then wonders why no one likes him in her family (husband and I like him). Why give people ammunition is what I tell her!
I would count your blessings and not give it another thought! She is probably jealous as others have said.