I was an elder for some time. One of the most recent memerial talks I gave was for an unbelieving husband. The wife was a struggling sister. Son had joined the marines corp one year before. He attended the memorial in his full dress marine uniform. The daughter wanted nothing to do with the Jehovah's witness religion. She attended with her boy friend. The audience was a mixture of witnesses and non witnesses. Even elders attended. The place was a funeral home. I gave the talk. The son spoke to the audience in his full dress marine uniform. The son spoke of his love for his father. He explained that he joined the marines because of his father. The last thing I did before the prayer was explain the deceased love of contry music. We then played the deceased's favorite country song.
After the ceremony the group stayed to talk to one another. No one said anything discouraging. To the contrary, all I heard was positive comments from witnesses and non witnesses. The son, daughter, and mom live with mutual respect for each others beliefs to this day. Much good came from that cooperation at the memorial.
All our circumstances are different. Not trying to make any rules here. Just sharing something that I was happy to be a part of as an elder in good standing.