I don't think that age really plays a huge factor in what instrument or instruments that someone could learn to use. I think the most important thing to keep in mind would be, knowing what you wanted. As long as you know exactly what you want, and are determined to do everything it takes to get it done, nothing can stand in your way!
I would suggest your Aunt just think about what she has always liked, and what seems like fun and go from there!
I've played the violin (not too well) and I've played the piano (good enough to keyboard for my school's jazz-rock band)...I'll go with Piano. Any church has a piano or organ (although the organ is a whole different ball of wax if it's one of the huge ones). I think a string like the guitar might be difficult, as would a brass like the trumpet or a woodwind like the flute or clarinet.
I think I've strummed a guitar once. I've played Piano for over 30 years. The attached off the streaming piano-lounge playlist I have online.It's not me singing the music--it's the greats like Bennett, Manilow, etc...but this "bump" to go between songs was produced by me.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.