If you are going as a family, I would suggest Boma. It is a buffet, with lots of different things, so that everyone can try something ,but if they don't like it, you didn't waste the money on a dinner & they can go get something they like. They have children's favorites like chicken tenders, macarnoi & cheese & other "normal" american dishes, but they may find they like some of the other items on the menu as well & it is fun going up & trying a sample of the desserts.
Jiko is much more romantic, higher prices & I don't recall if they even have a children's menu. My DH & I went there on our 25th anniversary & it was great, but even for me there were some things on the menu that we just not appealing. What I did get was great, however. Don't get me wrong there were children at the restaurant, but I think they'd have to more adventurous in their food choices. Debbie