She even expressed interest in taking part on twitter 2 or 3 weeks ago and mentioned OVER THE RAINBOW and Many Classic Moments. So it's probably likely to happen...perhaps the song she mentioned recording this week is for the album or no???
Personally I think Many Classic Moments is a perfect choice. I would also like to suggest Wanna Be A Dreammaker...get Timmy to do Marc's parts...the song wouldn't sound out of place on Love Again.