Annabelle Boucher wants the law changed after she paid £75,000 to David Rogers, despite him admitting to coercive and controlling behaviour.
Shalaleh Barlow says legal rulings on "alienating behaviour" take too long and are harming children.
A family law professor says a new study highlights how little people know about divorce.
A judge says the order cannot be overturned but the law firm says this verdict is a "bad decision".
The reforms had been due to come into force last year but are now expected in June 2024.
Both current and retired staff face "a severe and drastic impact" from the delays, say solicitors.
Ministers say mandatory mediation will cut court backlogs, but fears for coercive control victims are raised.
"I have asked your Mum and Dad to behave a bit better," Judge John McKendrick told the brothers.
One law firm says January sees more couples asking about divorce than the other winter months.
