When I started Isla on raw over a year ago she wouldn't eat the bones either at first. I had to smash the drumstick bone up a bit with a hammer so she could smell the marrow. Just enough so it would break open and she could see that it was indeed food. Now all I do is throw the piece at her and she goes to town!
I just started my cat on raw and had to do the same thing. He surprised me (since he's 13) and actually ate the smaller bones and marrow if I smashed them up. Since your pup is young still, she should figure it out soon that it's good eats!