Never seen any kids either...never wondered why though. But now I do. If they know how to behave...I say go for it! ^
Couple of thoughts: I always go for Lunch at 2 & 3*-restaurants if available. The atmosphere tends to be less ceremonial, and I am not much of a gala person anyway. Plus, I tend to get tired when it's all dark out and I'm sitting for a couple of hours, feasting. Might work out a bit better for the kids, too.
If you decide against the "Restaurant Gordon Ramsay", a few of his places have kids eat free deals. Obviously not as fancy, but still GR @:-)
https://www.gordonramsayrestaurants....kids-eat-free/