Who is female background singer for Sarah McLachlan?

The female background singer for Sarah McLachlan is Jill Sobule. Sobule has been a part of McLachlan's band since the early 1990s and has contributed vocals to many of McLachlan's albums, including "Fumbling Towards Ecstasy" (1993), "Surfacing" (1997), and "Afterglow" (2003). Sobule is also a successful solo artist in her own right, having released seven studio albums.