Really the answer is that anything's allowed - it's not a legal document but a personal record of the customer's family, so it's really up to them what information they would like to include. It's then my job to make it
(a) understandable and (b) beautiful.
So the heartache over whether to risk upsetting distant cousins - or even close relatives - by excluding them, is a very real issue for the customer to deal with, and there's no "Family Tree Rulebook" to guide them or defend them!
Every tree has some questions that arise for which I need to remember that this might be sensitive. I'm always happy to advise, but in the end it's not my call.
One of the tricky areas is around coats of arms - there are plenty of websites that suggest that everyone with the same family name shares the same coat of arms, which is definitely not the case. A coat of arms is granted to an individual and the honour is passed down through the family, with very specific heraldic rules governing how this happens.
So it's unlikely that an individual will be able to find their coat of arms by searching on the internet.
That said, if someone requests a certain emblem to be displayed with their family tree, then I will happily do that for them - I think I'm overstepping the mark if I do anything else.
(By the way, I did create a coat of arms for my dad - just for fun. It's got all sorts of elements personal to him, and the motto is - in Latin of course - "Turn that noise down!" which was a key phrase from my childhood!)
Want to gaze at a fabulous family tree? Here's Neil Bromley's tree for the British royal family - even amended to include Prince George! Click HERE