Friend passed away

Not really sure where to post this. My friend passed away a few months ago. Today is their birthday. The family has not changed the Facebook yet into a memorial page because they want to keep the ability to tag her and get notifications on things like birthdays.  So I have turned off the following cause don't want to be rude and unfriend her cause apparently the count her friend list 😐. Anyway so everyone is wishing them a happy birthday today. To me it feels morbid and I don't know what to say. Does it make me an ass if I don't tell them happy birthday?