Is Martha Stewart's daughter selling her Tribeca penthouse? Looks like she is judging from this $12.4 million Brown Harris Stevens listing for a four-bedroom, three-and-a-half-bath loft. A source in the know says it's indeed hers and that it just hit the market two weeks ago. Apropos for the daughter of the domestic diva, the duplex is Blueprint-mag-pictorial ready (read sleek and clutter-free) and features a super-luxe kitchen with not one but two stainless-steel refrigerators and dishwashers. (There's also some exercise equipment in the mezzanine, but we digress.) Last winter, Alexis, who co-hosts a talk show on Sirius Satellite Radio, bought three floors at the glassy 165 Charles Street, though press reports later pegged that purchase to her mother. It's not clear whether she'll be moving into the Richard Meier building herself. —S. Jhoanna Robledo