I was thinking the same thing. I didn't want to betray her trust even if she's not here. It just has been on my mind alot. He keeps mentioning it so I thought it may have been something he wanted to know but then I worried he'd get upset with me for not telling him. I guess it's because I'm close to him too. He and I were the closest ones to her.
As for the tattoo, I know they are forever, I have 5 already and I definitely am going to get one to honor her memory (she had 4). We both love tattoos. I looked on line today and I think I found one. Its the chinese symbol for "best friend". I was thinking about getting it with her name over it. I will never find another friend that I can be that upfront with and who accepts and loves me for my good qualities as well as my flaws like she did. She was a very special woman and there aren't very many people like her. I am grateful for the short time I did have her in my life even if I wasn't ready to give her up yet.