Family travel insurance-so do we have to insure as a group?

[mumma24]

We're a family of 3 adults and 3 kids (my daughter is 19 now)
Can't get family insurance so should we get group or is it better to insure one adult separately,

We have had to do that this year, as son now 18. Worked out cheaper. Lots of online insurers will only count a family if kids under 18. I spoke to a real live person on the phone at the company we eventually went with, and he said it was better to do that for some reason I can't remember, than a group policy.