It's not possible that you've ever met my granny?

What are the odds that I have?

Is your grandmother that nice old lady?

... Whatchu talkin' aboot, Moogs?

Isn't it possible I may have met his grandmother?

Wouldn't it be easier to judge if we were aware of your two respective locations both now and in the past?

Why would you be asking for our respective locations when our grandmothers lifelong travel locations would be what you need?

Should I have made it more obvious I was speaking of him and the lady in question?

Would you kindly rephrase the question?

Does it help if I say "him = the one that may have seen the grandma" and "lady = the grandma?"