Although the GAM live DVD does contain a lot of pre-GAM solo stuff from both of them (including Namida Girl which, incidntally, I'm using as the title of a story which I started writing almost ten years ago, and may or may not ever finish).
Chatin beat me to it
Her voice was very prominent in MoMusu songs, however. I think that the one where it comes across the most (at least for me) is 愛の園~Touch My Heart!, which was a good song for showcasing individual girls' lines.