I'm not sure how helpful this might be coming from a New Yorker () but we went to pubs nearly every night we were in London last month. I didn't see one which couldn't be considered child-friendly. Considering they are now smoke-free (), it's even better. We were in pubs in Islington and in Leicester Square. I don't see how you could go wrong especially if you think you'll be finished by 7:30. And we saw a few kids with their parents in these pubs.