No one has answered, so I will. I have not chartered with kids (I own my boat and go that route), but going with kids is a lot of fun. We had ours on board at 5 days... so the age is not a problem. Air conditioning will be an issue if you go when it is hot. I do not knwo if charter boats have a genny and ac. Opening the
hatches at night will about freeze you out, but you need to take a netting to keep the no-seeums off (not mosquitoes, mind you, no-seeums). We had a very miniature covered playard made by Fisher Price that worked very well. It is a half-dome on stands with a zip-up netting. Never had a problem with bugs and Chase loved it.
Take a lot of bug spray and good SPF (water babies) for the youngster. Their fair skin will get sun burned even under a bimini all day. Pack for a long week like you were going camping, and you will be fine.
Hope that helps. Let me know is you have any specifics.
- CD