''I'm one of the ones that doesn't whine I say, 'Get on with it, get on with it! Stop complaining!''' Patricia Kalember is talking about her thirtysomething character, the no-nonsense Susannah Hart (widow of Gary Shepherd), but it's not a bad self-description either: This season, the 34-year-old actress shuttled between homes in New York and L.A. and jobs on two series (her newest, Sisters, airs Saturdays at 10 on NBC), with her husband, British actor-director Daniel Gerroll, and their kids, Rebecca, 5, and Benjamin, 2, in tow. The busy schedule was just what Kalember wanted, and so was the jump from Susannah (''I absolutely loved her, but people really don't like her, do they?'') to the more nurturing, even-tempered Georgie: ''thirtysomething was great fun because the writers were so interested in the minutiae and messiness of life. But Sisters is fuller and cleaner and simpler it's slightly heightened, even a little theatrical.'' While NBC watches the show's ratings (Sisters' premiere beat CBS and ABC), Kalember won't think that far ahead. ''I'd love the series to succeed,'' she says. ''But we have two kids and another life, so I'm not going to worry about it.''