Because kids want to find where they come from, and form an identity, and understand their place in the world. A big question in her life has got to be where did her dad go and why. And maybe she is hoping she will get to ask him, face to face, and that he will give her some reassuring answer.
Or she can at least see the place, and feel her roots there. You remember being 14, don't you? It is a difficult age in a lot of ways, and more so if you don't feel that you are whole and complete.
A kid with a missing parent often doesn't feel whole and complete, often in ways they can not verbalize. It has nothing to do with how you have been as a parent - she has a piece of her that is missing. Combine that with the famous 14 year old inability to understand the big picture and the practical limitations of the situation.
Bless that optimistic idealism. If you truly can not manage any travel, then be willing and open to talk to her about whatever she needs to understand. Telling her that dad is a "not a good role model" isn't the truth - and it makes her think you are just saying no for no good reason.
Be open and honest, and it may be time to tell her some more specific information about your concerns. You can also consider talking with a counselor, both to give you some ideas about how to approach the conversations and how to handle her requests, and to give her someone to talk to about it that is outside her home.
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.