Try the closest domestic violence shelter/group. They have a court advocate -- and they know the judges on their court circuit. There may be a judge who will sign a protection order for MIL.
Find them on the 'Net now and talk to them. Stalker may be known to them, which will protect your MIL.
Our domestic violence/family crisis service agency is in the same building as my office. Sometimes, they ask a woman to come back the next day, or say on Tuesday, when the "right" judge will be available. Who you know matters!
Sorry to hear about the whole sorry mess, notmoose
Doug, thanks for protecting your family. When this is resolved, MIL may still be interested since she knows for sure that you protect those close to you! Too bad Doug's ex thinks this Stalker guy is OK. Maybe Stalker will say something to her kids that gets her on the other side of the fence.