Tell her to go back to the Police and report this as Harrasment. He will be arrested and interviewed. They will issue him with a harrassment notice, which will stipulate the terms of his release as agreed with the victim ie not to speak directly to her unless it involves the children, not to phone or text her, not to enter her property without permission.
If he breaks this he will be rearrested and charged under the harrassment act. Punishment for this, depending on severity, violence, abuse and mitigating circumstances will range from a cautoin to a custodial sentance.