Is this offensive?

Bl
Well my SO aunt came to visit a couple weeks ago and we went out for dinner with the family. She asked us, "when are you gonna have some black baby's?" I'm black SO is white. I didn't know how to take it I would've preferred if she said "when are you gonna have babies"? Like why add race to it? She's like 60 something and I didn't say anything back out of respect for older people. She asked the same thing a couple years ago when she visited before. Just rubs me the wrong way. Would u find it offensive?