The development comes at a difficult time for Herbalife, which has been at the centre of a dispute between well known investors Bill Ackman and Carl Icahn.
Gay rights groups are lobbying aggressively for the gay marriage language to be included and they dispute suggestions that it would jeopardize the bill.
Watts and Coverdell joined a group of Republican lawmakers at a news conference to dispute reports that their attempt to push their tax cut bill last month with about 600 town hall meetings was a failure.
She said her bill would require factoring companies to be accredited before they could be registered and would make them agree to a new dispute resolution procedure.