While Bravo and the Richards' camp have yet to officially confirm she's in treatment...
Last night, Kyle Richards gave an update on her big sis and costar's well-being.
"She's doing very well, thank you," Kyle told reporters at the Disney on Ice and AEG's Seasons of Giving premiere of Toy Story 3 in L.A. "That's all I'm going to say. She's doing fantastic."
Whatever is going on, it's certainly not keeping Kyle from enjoying some good ol'-fashioned holiday cheer—south of the border!
"My family's so big and nobody can agree on one place so we're going to go to Mexico for a little sun and then we're going to go off to the mountains for some snow," she said. "I really just wanted the snow but my older daughters are like, 'We want to be in the sun.'"