The life insurance is for the SM family and the CPs should be paying the premium.
Not sure how much they would insure for.
In the past I worked in insurance doing medical interviews for life and income protection policies. Life policies are often connected to a mortgage so that if one party dies the mortgage is cleared and there may be a modest additional benefit. But if you are low income you can't just go and take out insurance for a million + the amount is normally expected to be at an equivalent level for income. Excessive amounts raise suspicion with the underwriters.
That said to truly compensate for the loss of a mother to a family, depending on the number and age of existing children one should really be calculating the cost of nanny, cook, cleaner, etc for a surviving parent to cover all those roles to age 18 so the amount would soon add up and a realistic sum might be well over a million.