If it's not going to be a surprise to her. Let her pick. She will be more proud.
If the boyer you choose uses veneers, the type of wood won't affect the bow enough to make a difference so pick away.
I built my wife a bow with some beautiful Coco. She liked it enough. Later, with her permission, I sold it at a shoot. There was a young lady there that just couldn't live without it and I didn't have any more in that pound category.
For her new bow, I asked my wife to pick out the wood. She picked myrtl burl. She seems to be more attached to this one, I think because she took part in the decision process.
bigjim
BigJim