BTW - Canadian law largely finds in favour of the mother in the case of separation / divorce when it comes to the custody of the children. You can see statistics here:
https://www.justice.gc.ca/eng/rp-pr/fl-lf/famil/stat2000/p4.html
Your husband is the one at a disadvantage here - not you.
@scylla wonderful advice really!
let us say she gets separated, get sole custody of her children and even wins child support
Hurrah !
now this is what might happen
her children will grow up without their real father around. we know how that works out.
children suffer the most in such cases
he might even go back home, get married again, start a new life with his young wife, and take his toxic parents with him. come back again and settle in US or another province etc. he will a lot better off unless he loves his kids too much. And so much for paying child support and the ruling and the case etc will be a total waste of time. or he might even runway before the case even begin.
she will end up trying to raise the kids all by herself, while paying the bills etc
there might be even huge lawyers bills that she might have to deal with for the rest of her life
she will need a nanny as she will be too busy trying to make a living
she wont be able to find a decent husband or partner again.
i mean who in the right mind would want to marry someone with excess baggage
once the kids are grown up, she will find herself in the same situation as her toxic in-laws
few years down the road while playing candy crush on her broken phone in a nursing home somewhere while waiting for a visit from one of her kids, she will be wondering why she even listened to some strangers on the net!
are you okay with that scylla?
all she had to do was to serve tea and biscuits on time and tried to make it work