Mary Offley, died young - Incorrect Display Name

Looks correct for me. Nobody have a comma in their name, so it is obvious that the part after the comma is a suffix/information

died young should be in the Cause of death field.

There are a lot of different ways to express "died young" and while YOU may not like it in the Display Name, it may be a useful practice.

I use Died Young in the image usually.

What you do need is something that tells people not to merge the profile with a sibling with the same name. And the Display Name works too.

There are a lot of more concerning matters.

Died young is not a cause of death. A cause of death would be like crucifixion, self-immolation, burned by acid, shot by a leader of ISIS, or brazen bull. Died young is a note. And the fact that someone from the 17th century has no kids usually means he or she died young because most people back then reproduced, it's not like today where people can attain happiness when alone thanks to internet pornography.

We all have our own ways to state it as a fact.

I choose to put it in the cause of death field.