no. 1883 for the year 2003 which includes the following:

A wife whose husband passed away was still in her `idda [waiting period] when her daughter came from Canada to take her to live with her there. The daughter was to depart four days before her mother's `idda was due to expire. Please take into account that the mother cannot travel alone and at the same time does not want to disobey the Shari'ah by traveling before her `idda expires. Moreover, she will be staying at her daughter's house for six months at least, not for recreational purposes.

What is the legal stance of this situation?

It is established in the Shari’ah that a wife whose husband passes away must observe her 'idda, which is four months and ten days, in her house except when necessary to do otherwise.

The Ruling
There is no objection if the widow mentioned in the question travels with her daughter to Canada provided that her daughter's departure has already been scheduled and she cannot travel alone which is known by scholars as fear of travelling without trustworthy companions to ensure her safety.