I know, I know! The last thing TV viewers need is another sitcom about an oddball extended family.

And yes, “Three Sisters” (debuting at 9:30 tonight on NBC) is so packed with female bonding that you may think you’ve accidentally switched to Lifetime or Oxygen. The estrogen just flows in this ensemble comedy.

And still “Three Sisters” has its moments, which is more than its predecessor in its time slot, “DAG,” could ever say. (“DAG” moves to 8:30, replacing Michael Richards’ even more laugh-challenged vehicle.)

The show is narrated by architect Steven Keats (played by David Alan Basche), who is married to a nurturing older sister, Bess (Katherine LaNasa). But in marrying Bess, Steven also inherited her two sisters: sardonic middle sister, Nora (Vicki Lewis, “NewsRadio”) and flighty youngest sister, Annie (A.J. Langer, “It’s Like, You Know…”). Also dropping by frequently is the women’s mother, the vivacious Honey Bernstein-Flynn (Dyan Cannon, “Ally McBeal”), and their bemused father, George (Peter Bonerz, “The Bob Newhart Show”).

Through the often-befuddled Steven, the show’s straight man, viewers get to study the interrelationships, sometimes amusing, sometimes poignant, among the Bernstein-Flynns.

The series has two proven scene-stealers in Lewis, who gives documentary filmmaker Nora a sardonic edge, and Langer, whose Annie is still blissfully seeking her place in the sun. It has a talented cast that deserves better than the hit-and-miss material and way too many Hallmark moments that “Three Sisters” is made up of.

Created by the writing team of Eileen Heisler and DeAnn Heline (“Ellen,” “Roseanne,” “Murphy Brown,” see a pattern?), “Three Sisters,” although uneven, still deserves a good look by NBC, which keeps such drek as “DAG” and “The Weber Show” on the air.