"Mother!" (She calls me 'mother' these days. I don't like it but I have decided to pick my battles.)
"Mother. This is a serious question. What if I'm a musketeer and I have two horses. How do I get to town?"
"That is easy," I tell her. "You ride on one horse and you tether the other one to the horse you're riding on.
"I don't want to be a musketeer anymore," she answers me. "It's too hard. What if I cut myself with my sword?"
That seems like a legitimate concern.
"That is why you practice. Most things are hard at the beginning. Do you think being an artist, a farmer, and a biologist (her other chosen professions) is easy?"
"My friends will laugh at me. I'll be the silliest musketeer ever!"
I set her on my lap, my silly musketeer with the serious concerns, and we snuggle for awhile. I tell her she has time to think about it. All the time in the world.