Imma-Jane Potty Mouth!

I was once told, when Imma was about three, that she was fully incapable of understanding jokes.  I was speaking to someone involved in her autism evaluation and I asked, "Are most 3 year olds capable of understanding jokes?"  I was told, yes they can.  But Imma can't.  I began asking my friends if their children could understand jokes at 3 and most of them said no, not really.  So, I asked for clarification again, as this was being used as a sign of her autism, "Are you sure that most 3 year olds understand humor in general? Are you saying you tell her a joke and she doesn't get it, that she can't tell a joke?  Do you use the same jokes for all ages to be able to tell if they understand or are there specific jokes for each age?" and once again I was told, "Imma is not capable of understanding when somone is joking, nor can she tell a joke."  Really? Really.
So, even though it is just awful that my child recently started telling potty-humor jokes, I have to admit, I'm actually a little relieved and part of me wants to say, "In your face, evaluation team!" Because, while I would not say that her jokes are funny per se, she definitely knows how to tell a joke and she gets it when someone else is telling one. Especially if it has to do with going to the bathroom.  This is our great topic of late.  Her favorite new song goes like this:
"If you're happy and you know it, Daddy go poo-poo!
If you're happy and you know it, Mommy go pee-pee!" etc.
And as far as she is concerned, this is hilarious.  Lucy thinks it is a riot as well and she will join in and sing along, which is just more proof that Lucy is right on track developmentally, thank goodness.
I would definitely not say I am rejoicing that my child is telling potty-humor jokes, but at the same time it is nice to know that she gets it, she finds it funny, she likes telling jokes and having people laugh.  It's another form of interaction and another developmental milestone that she actually hit just about on time for what I can tell.  I think most 5 year olds probably still think potty-jokes are funny. So, of course I tell her to quit but a little piece of me is still happy to hear them.

My goofy girl!

What experiences have you had with your kids telling jokes in general or bathroom-humor jokes?  How old were they?  In your experience, do 3 year olds fully understand jokes?