Usher's ex-wife lashes out at Usher's girlfriend, calls her barren

Usher and a girl friend Grace Miguel

Ex wife Tameka

Usher and his ex-wife Tameka Raymond are currently going through a bitter child custody battle and Tameka blames Usher's girlfriend and manager, Grace Miguel, for the whole mess. Calling her barren and infertile is a little extreme. What do u think guys?