What legal action can be taken against someone who makes continual false reports of neglect to Social Services?

The remedey here is to first write a letter to this lady informing her that any further attempts on her part to make a report regarding your granddaughter will be reported to the state authorities.  the fact that this lady is making claims that are false is a crime in and of itself.  Indeed, making a false report to the state is a crime.  furthermore, the claim is also defamatory to an extent as your reputation is injured.  Moreover, her conduct is an abuse of process - i.e. she is making a claim that is false to harass and annoy you.  You need to explaint that you will take legal action against her is another report is made.  you should then send a copy to the police department in her town and social services to place everyone on notice.  if she makes another report, you will have a written record to use and will have ground for her being arrested.