I'm still completely flabbergasted and don't even know how to tell this story.

My kid spent the day at home because there was teacher's inservice at my son's Kindergarten class this week, and I had volunteered to watch one of his classmates because her mother had to work. If it had been just my little boy, I would have set him down in front of Lego Indiana Jones to be a sofa boy all day long, but I didn't want her to think I was a neglectful mother, so I planned 'activities' to keep the children occupied. We colored. We fed the fish. We walked to the park and played on the swings.

During the course of the day, we had a few lulls in the pace, and at one point, my youngster asked if he could show his friend the car I was "renting." (His term for the manufacturer vehicles I am sometimes loaned to review).

My little boy gave a very good tour of the beautiful Audi in our garage this week, and thoughtfully demonstrated the fold-down third-row seats, the two sunroofs, the side and rear window sunshades, and the cabin lighting. (This kid might become a salesperson!) But his favorite thing was the center fold-down armrest with the telescoping cup holders, because it fit so nicely next to his booster seat. He folded it down, and said, "Look at this!"

After which, she promptly sat on it.

I said, "Oh no, Sweetie, you can't sit on that, it's not meant to hold your weight," (What I was actually thinking was "Oh no, Sweetie, DON'T BREAK MY LOAN CAR, THE FLEET PEOPLE DON'T LIKE IT WHEN WE BREAK THINGS IN THE CAR!) and she said to me, "Oh, I have a seat just like this in my Mom's car!"

So I say, "That's great!" and then start doing a mental review of cars that I know have factory-installed booster seats in the second row. Volvo XC90 has a great second-row center booster seat. Chrysler also offers an integrated child booster seat in the Town & Country and the Journey. Are there others? These are just the few that popped directly into my mind.

I didn't think much about it, until the end of the day, when Mom showed up to pick up her daughter. I walked them out to the car, and as she and I chatted about the lovely day our two children spent together, her little Sweetie climbed into the second row of her SUV (which was neither a Chrysler nor a Volvo), and sat herself on the center armrest. Mom reached in and used the three-point center seat belt to buckle her in place.

She's six. I have no idea how much she weighs, or whether she is taller than the 4'9" height recommended before transition into an adult safety belt is considered safe. This is one of the first times I've had a conversation with this woman. And I was completely flabbergasted. I didn't know what to say! (okay, okay, I know what I wanted to say, but every time my brain tried to reach for a more delicate, discrete way to discuss child seat safety, I had to close my mouth to stop from delivering the actual words--"ARE YOU REALLY THAT STUPID?"--which kept trying to jump out.

I don't want to make this lady mad, it's a small school and our children are likely to be in the same class together for the next several years. I need to take a breath, and figure out a more courteous way to mention my feelings about car seat safety with her. Another friend of mine has already told me it is none of my business.

What would you have done? How do you recommend I approach this subject with her? I'm willing to take suggestions here, because I know it is important.

Thanks for letting me vent.