How would you guys respond to my girlfriends question?

Had the marriage conversation with the girlfriend. My mom's on disability who raised me thru hell. She sacrificed a lot and shes very dear to me. My girlfriend is very adamant she wants to move soonish and I do as well. I knew that she wanted to move from the beginning of the relationship. It sucks to leave my mom behind, but it's part of life, I guess. Lately, we've been having conversations about marriage, and she was asking questions along the lines of my mom vs. her. For example, if my mom wanted me to stay just out of emotional reasons, would I stay? I said no as my commitment is to you, etc. If my mom got hit by a car, then I'd stay until she gets healthy, etc. The Gf is fine with that and understanding.
Today, she asked what I think is a little bit of a messed-up question : if I was giving birth and was due in a week and your mom got hit by a car, who would you pick?
I said that's a pretty ****ed question that no guy can answer clearly right away. She's adamant that the answer should be very clear and it's her. Ngl the fact that she even asked this question makes me doubt who I'm dating. I get that wife is #1 but it still feels messed.
Guys you are firing on all cylinders to the point where I don't know who to answer/where to start. I'll repost this with much more context.
Thank you everyone for sharing and responding.


Source.

@Sparky: seems like a question that shouldn't be asked...I would say mom is first unless the gf is really really loyal