An affidavit filed two days ago by a psychologist says a guardian ad litem should be appointed for the Sanfords' 16-year-old son.
The psychologist said in the affidavit she does not believe it is "beneficial to a therapeutic relationship" for her to testify in court, but that she would be willing to speak with a guardian about observations that the guardian could then convey to the court.
Jenny Sanford asked for a guardian just over two weeks ago, at the same time she asked the court to make Mark Sanford undergo a psychiatric evaluation and enter anger management.
A family court judge said Monday the Sanfords would have 30 days to settle their differences in mediation, but that the timeline has not yet begun.
Congressman Sanford has denied his ex-wife's accusations, and claimed on Facebook that she was denying him visitation with his son.
He has also said a guardian is unnecessary.
This past Monday, the Sanfords canceled a family court hearing in Charleston County because they said were trying to work out their differences on their own.
The Sanfords divorced in 2010, one year after then Governor Mark Sanford went public about his affair.