Whitney Houstons mother, Cissy Houston, declined an offer to attend Clive Daviss pre-Grammys party in Los Angeles Saturday night, opting instead to attend church Sunday morning, the day before the first anniversary of her daughter's death.

She was surprisingly in good spirits. Emotional at times during the service but good and tough as usual, Alexis Houston, who claims to be Whitneys half-sister, tells The Huffington Post. I spoke with Cissy this morning at church. Im not in communication with Pat or Gary," she said, referring to Whitneys brother and his wife, who both attended Davis's party in LA at the Beverly Hilton, the same hotel where the singer died a year ago.

On Thursday, Cissy, 79, responded to Davis's invitation to his pre-Grammys party. Although Davis was her late daughter's mentor, Cissy told "Access Hollywood" that the invitation was obscene.

Clive's party could have been moved, but I guess the venue is legendary and he does have a loyal relationship with them, says Alexis. We celebrated this [Sunday] morning at New Hope Baptist Church [the same church where Whitneys funeral was held] with a commemorative service.

Alexis is no stranger to controversy. In 2010 she held a press conference with Gloria Allred to deny reports she was having an affair with "Today Show" host Matt Lauer. The New York Post reported in 2010 that Alexis was born a man , and used to be called Wellington Houston, something Alexis denied at the time.

PHOTO of Cissy Houston courtesy of Darnell Thompson: