Thanks all for the replies! I think for now I'll stick with the medium mice and see how she does the next month or two. I would hate to split her neck which I think a large mouse would do . The medium fit in her mouth perfectly and there was a small bump as the mouse progressed so I think medium mice it will be. I'll keep an eye on her weight and keep an eye on any behavior that would indicate she's hungry earlier than feeding day.

I was just surprised at how much her neck had to stretch that short way as my 2012 female Normal's (113g) neck doesn't stretch that much with fuzzy mice and was was a little worried. Maybe I need to up my Normal to hoppers...