A lot will depend on how far they got with the plumbing and electrical, what was already permitted and inspected, and what was just abandoned.You will certainly need a GC to deal with the permitting and inspections.It could easily be $50k to $100k or more, depending on what has been done, what hasn't been done, and what has to be re-done.That being said, a friend gave me some excellent advice about estimating rehab costs once that I've never forgotten: "Add up exactly what you think it's going to cost, then double it!".

The house really is in excellent condition.

The lender may decide to retain the loan (in cases of excellent credit) or bundle, package and sell the loan to replace lost liquidity.

A solid read on investing in Canada is "Legal, Tax & Accounting Strategies for the Canadian Real Estate Investor" (Cohen and Dube).If you are willing to go cross-continent, there are markets with excellent cash flow, especially in MF properties.

Excel will come out and locate the leak for her.

Excellent, detailed post.  

Mark,Adrien brought up some excellent points.

It's all a numbers game and easily projected on an excel sheet.

Dave Meyer did an excellent video for BP on YouTube for this very topic; multi family units.

"long-term tenants with a pride of ownership mentality," an excellent nugget of information!