Criminal Harassment can carry a max sentence of up to a 10 years. Posting on the mother's FB certainly falls under the legal definition of criminal harassment. They don't live in the US tho, so not sure how their country views it. If anything, I thought European countries were harder on stuff like that, but I haven't followed this story at all. I just popped in this morning and made a quick comment lol.
Generally, criminal harassment entails intentionally targeting someone else with behavior that is meant to alarm, annoy, torment or terrorize them. Not all petty annoyances constitute harassment. ... Harassment charges can range from misdemeanor to high level felony charges.
edit: I am very much for free speech, but I don't consider it free speech/expression to target a mom like this. I consider it malicious and nothing to do with free speech. So if a case like this ever saw a trial, I would hope the judge would throw the book at them.