E.E.
Hi,
I read about this recently as I have a 6 month old. For newborns it's just hard for them to coordinate their pushing with the sphinter relaxation at the same time. As long as she isn't constipated there really isn't much you can do. You could try pushing her knees to her chest (worked some with my son) but you've just gotta let her work it out. It will just get better and easier for her with time (probably not very long). Good luck!
E.