Should I file MFJ or MFS?

My wife and her three children have not lived in my home since July 1, 2019.  She was indicted in October 2019 on Federal fraud charges by the VA.  We're not speaking and I would like to file my taxes.  I have 3 filing options:

 

  1. I can file as MFJ and claim her 3 kids as dependents. ($11,500 refund from both Federal and state)
  2. I can file as MFJ and not claim her 3 kids as dependents.  ($4000 refund from both Federal and state) 
  3. I can file as MFS and not claim her 3 kids as dependents. (I owe the IRS $7300)

She has an agreement setup with the Father to claim the children on her taxes.  I'm not sure if she has filed her taxes or not.  Obviously, the return would reject if she has filed her taxes and I'm trying to claim her children.  That would leave me with option 2, which is great.  I'm trying to avoid option 3, and prison, at all costs.  I would hate for fear to drive me to option 3 when I don't need to file as MFS.  PLEASE HELP.