Melissa Etheridge & Tammy Lynn Michaels Continue To Battle Over Custody Of Twins

TMZ reports that singer Melissa Etheridge and estranged partner Tammy Lynn Michaels are still struggling to come to an agreement over the custody of their 4-year-old twins, Miller and Johnnie Rose.

According to legal documents obtained by the site, Etheridge, 50, and Michaels, 30, have yet to settle on custody, child support, spousal support, visitation, and the division of their property, with the legality of their 2003 union being the central issue of the dispute.

While Tammy claims that the couple was married, which entitles her to more of Etheridge's assets, the Grammy-winning artist contends that their exchanging of vows was not legal.

In July of 2010, Michaels' wrote that she was "blindsided" by news that Etheridge had filed a Petition for Dissolution of Domestic Partnership, "even though we both promised, agreed, handshook, pinkyswore no filing until after tour in the fall. [H]er broken promises told to me by headlines."