Is there an age limit for children in the evening?

No

No age limit!

We had a whole school bus full of kids there ranging in age from 6-16. I think it is more that it gets fairly loud at night with the bands and small children may not enjoy themselves very much, ergo the parents may find themselves with an unhappy toddler on their hands. So it is probably best to see if there is a live band or not playing on the night you want to bring the kiddos.

We went for a meal fairly late and there were still families in there so I'd say there isn't.

I don't think so. I saw kids there in the evening