I might be over thinking this but here goes!
My colleagues DM has passed away, so I am going to go and buy some flowers and a card later today.
Her DF had already moved in with her family so he could be taken care of in the future. I do know her DF also, as we grew up nearby to one another anyway
So do I buy the one sympathy card and address it to all the family or do I buy one card for my friend and her sons and one for her DF separately?