Lost Job. Lost TN Visa. Now What?

My friend has working the USA on a TN Visa for 15 months. She got fired or resigned — depending on who is telling the story. Her last day is this Friday. She's in a depressed area of the USA, so there is little possibility of getting a job offer for a new TN Visa on short notice. She is currently enrolled in a part-time Master's degree program at a local University. She wants to stay in the USA at least until she finishes summer courses in August. What are her options?

Should she immediately apply for conversion to a six month Canadian Tourist Visa? What is the correct form to use ? I-539 ? What wording should be on the petition?

Can she continue to go to school legally on the I-539? Should she apply for a Student Visa? She has some savings, but not an extravagant amount. As a legal resident (and taxpayer), she pays resident tuition fees.

If she is in the USA on a Tourist Visa, then presents at the border in a few months for a new TN Visa with a new prospective employer, will her lack of a Canadian address spoil her TN Visa application?

Any other thoughts? Many TN Visa holders simply overstay and continue with school without bothering to get other visas.