Police charged Kashmire Dawson, 24, of 427 Albany Ave. with assault and possession of a dangerous weapon after the 3:53 a.m. incident Sunday.
Her 26-year-old victim was treated for a cut on her right hand at a hospital, police said.
A police spokesman said the two were removed from Rumors by security shortly after arguing in the bathroom over whether to tip the attendant. The spokesman said he did not know Dawson's stance on the matter.
She was scheduled to be arraigned at First District Court in Hempstead Sunday.