Who Can enforce truancy laws in Ontario Canada? But she did…

Thank you
I am Step mom
We have a basic CO , every other weekend, half of holidays, fathers day and dad has access to get info first hand from all services providers. We do not communicate with mom as she is high conflict. FACS Niagara has been involved with her house since May 2017. She has a 17 year old at home from another relationship (he has not gone to school for past 2 years!). FACS is not doing anything other than making appointments at home once a month. Tells dad very little (privacy laws?) and con 10 years has switched schools Jan 2019 for 3rd time. Has not been attending all 3 schools.

Absolutely, thank you. I was thinking this:
"But, he could also seek can order requiring the mother to insist that the child go to school and then if she does not he can seek a finding of contempt against the mother".
He is able to give input but she makes final decision. His input was there's no point in switching schools when the real issue is that mom and older brother are not getting him off to school.
From what we know he kicks up a fuss (to stay home and play video games). At regular school he would act out just to get sent home (again, to play video games).
In our dealing with FACS we have been told "but she is a single mom it's hard", "this is not a protection issue" "you send too many emails" that was from the Supervisor. At this point we are on business day 9 of waiting to hear back from the FAC worker about this current school and attendance issues.
We live 1.25 hours away from their home.
They did say if they apprehended hey would be looking to family. But again, not a protection issue so they have no plans to do so. He also has a sister, my fiancé's daughter 9 year. She is starting to display behavioural issues at home and school and she loves school.
We met with a lawyer who said it would cost around 40,000 to go for custody and take up to 2 years and we could possibly lose if FACS isn't seeing any major issues the court will not either.
We're open to any and all suggestions :)

Thank you, ***** *****!
Do you think it would be helpful to start with an application against mom re: school and then once there is contempt go for custody?
I'm 100% sure that mom is clinging on tight due to child support and child tax benefits and such. Last summer (because she wants time to party) she was going to move near us to do 50/50 but then decided against it because "then I won't get support or to claim them and I'm trying to save money". Unacceptable.

Thanks my fiancé also thinks this is a good plan. What would be next steps is he doesn't go to school? Are there consequences for her? Or do we have to file contempt and maybe for sole or residential custody?Background: When we filed an urgent motion we had an expedited date granted. She was upset about our relationship because he was happy and not at her beckon call for the kids. She had not let him see them for 9 weeks. She said no to everything we filed. But summer came and she wanted freedom so she agreed to mediation and we got everything we thought we wanted. She had a legal aid lawyer, we filed on our own. We didn't know any better, thought sole was same as residential. In hindsight I would have shot a lot higher but we were so upset about not seeing them didn't want to completely tick her off.She's currently in contempt but nothing worth filing for. Did not get them passports, have access to all service providers yet we don't know who half of them are.And we didn't know to put communication in so we get no calls from the kids.

Thank you
You have been very helpful
At this time we cannot retain a lawyer. There is an extra component to all of this. BM's jealousy got out of hand. She tried to get me to break it off with him and vice versa. When she realized it wasn't going to happen she called the police and had him charged with sexually assaulting her. It is of course untrue. No evidence, he said she said costing us $45,000. As soon as trial is over next month we will have to file on our own to help these kids that have been through the ringer for almost 2 years. Very scary time for men out there. Wish us luck!