proof of age for big kids

[QueenGoblin]

I would think the most a CM would do is ask the child to tell his/her age. For an older child, maybe they would ask the birth year. I haven't seen it happen, but I know I have read/heard about CMs questioning children if they are suspicious about the children's ages.
As far as a birth certificate being a valid form of ID, a state issued birth certificate with a raised seal along with parents with IDs who match the names on the birth certificate is about as official as you are going to get with a child unless you have a passport. And guess what you need to show to get a passport for a child? Yup, a birth certificate and have both parents present with IDs that match the names on the certificate. Could someone commit fraud and try and pass one person off as another? Sure, just like you can commit fraud with altered ID's, pasports, etc.
I guess what I am saying is, I doubt anyone will say anything to you, and if they do question, they will probably take your/your child's word for it. These people see enough kids to know height/appearance of maturity can vary. But if you want some piece of mind bring the birth certificate (or a copy) along. It will take up a whisper of space in your packing and might save you a minute or two in line, who knows?
Have a great trip!

 

[slo]

You should go get an ID made at the BMV for each of your boys and carry it with your drivers license. I have one for each of my girls, and I have used it alot.

 

[QueenGoblin]

The DMV IDs are not a bad idea. I had one when I was a kid and we made a trip to Canada. My DH had one for a while b/c he did not have a liscence until he was in his 20's (grew up in Boston where they believe in pubic transportation.) Some places won't accept them as official IDs because they are pretty easy to get/forge, but if you are just looking for something with a name, photo and a birthday on it to back you up its not a bad thing to have.