They certainly have grounds. You have indicated that DYFS took her other children already. Assuming they had grounds in that case, she now has another child in her care. Why would you or DYFS assume that she could care for that child any better than she cared for her other children?
Keep in mind that this information is given based on the scanty facts that you have provided. And no one can rely on advice from an attorney who has not been retained. In order to be able to rely upon any advice, you need to meet with and retain an attorney, who will be able to give you advice after a full and comprehensive interview. Before you do anything, you should contact an attorney for a full consultation. Good Luck! Rob Gleaner