Does divorce affect Canadian Permanent Residence status?

This post is for a friend. She got to Canada after marrying her Canadian citizen husband. She has been in Canada for 4 years and got her PR.

Now there exists some serious, but non-violent issues between them and they are planning a divorce. She is scared that the divorce may affect her PR status as she got that because of the marriage.

She contacted an immigration lawyer named Matthew Jeffery in Toronto (matthewjeffery.com) who assured her that such possibility is very low.

She is still worried. I would like to know if there are some rare cases that affected the immigration status. Any suggestions on anything that could do to avoid such a risk?