Hi
how unfortunate, but nothing to worry about, what she has to do now is to get in touch with respective embassy via email or fax and expalin them circumstances sorrounding her. As they have come through all the way to end, i believe CHC will still grant her and family to enter into Canada on production of some docs. probably.
Ask her to contact CHC as soon as she can and they'll give her the best advise.
May her husband's soul R.I.P.
Sorry but don't give the OP's friend false hope. With the principle applicant deceased and the widow a housewife with 3 kids, the application has pretty close to a nil chance of success.
PMM