Kile Glover died from heart failure two weeks ago after being left brain dead following a jet ski accident.
Usher had asked a court to delay the next hearing in their child custody battle following Kile's death, claiming it would cause "unnecessary stress and strain" for both himself, Tameka and their two children "in the immediate wake of this tragedy".
He also stated that Tameka would have an unfair advantage in the hearing given the circumstances.
In court documents obtained by TMZ, Tameka states that Usher's "stress and strain" is "bogus" and that he simply wants sympathy from the media and fans.
"[Usher] visited Kile in the hospital only once" during his 15 days on life support, Tameka claims.
She also says he refused to tweet a message asking fans to "pray for Kile" and didn't attend Kile's funeral.
Tameka called Usher's request to postpone the hearing "a transparent sham" and asked the judge to go ahead with the August 13 court date.