The plaintiff, Tama Colson, says in the federal lawsuit that a male supervisor showed her a picture of a male sex organ last October.
The lawsuit, filed Wednesday, says the man became her supervisor earlier this year and began a "campaign of torment," and that she was demoted when she complained and eventually was fired.
Art Franklin, a spokesman for the church, said in a statement that New Birth requires employees to report abuse within 48 hours and that Colson did not complain until August. He says an investigation has begun.
Long is not named in the lawsuit. He's facing lawsuits by four men who claim he coerced them into sexual relations.