Felicity Bassouls, 67, appeared at Northampton Magistrates' Court where she was charged with harassing the former England player and Strictly Come Dancing star between September and October last year following his separation from her daughter Abby.
At the time, Cohen, 36, denied rumours that the marriage was ended by the 'curse' of the BBC1 dancing show after he appeared on it with Kristina Rihanoff.
He wrote on Facebook at the time: "It is a sad world when two adults cannot have a friendship."
A three-day trial was set down to start at Corby Magistrates' Court on August 12, with the agreement of defence lawyers and the Crown Prosecution Service.
Bassouls, from Ardross, near Alness in Highland, Scotland, is also accused of harassing her own son, Austen Blaney, with emails and phone calls, between September 1 and October 29.
She was unconditionally bailed after the hearing.
Cohen, a former Northampton Saints player, is the founder of The Ben Cohen Stand Up Foundation, which aims to raise awareness of the damaging effects of bullying.
In a statement issued at the time of the split, the couple said: "Ben and Abby Cohen have agreed to take time apart to deal with some marital issues but remain fully committed to the welfare of their children.
"There is no third party involved, and Ben and Abby now ask that their privacy and that of their family be respected at this difficult time."
The couple have been married for 11 years and have twin daughters.