'Basketball Wives' Star's Husband -- Alleged Baby Mama Wants $$$ for Secret Child

Former NBA star Eric Williams -- the estranged husband of "BB Wives" star Jennifer Williams -- allegedly had a secret child in 2011 ... and now the baby mama wants him to pony up some child support ASAP.

Tavia Serena Cannon filed a Complaint for Support in PA last week, she claims she had a child with Eric in October 2011. Cannon says she makes $300/week babysitting and wants Williams to fork over some cash and medical coverage for the kid.

Here's the rub ... at the time the baby was allegedly conceived -- Jan/Feb 2011 -- the former NBAer was still married to Jennifer ... who didn't file for divorce until June 2011.

Sources close to Jennifer tell TMZ this news comes as a shock. They claim the "BB Wife" had NO CLUE about the child. Their divorce is still pending in a NJ court.