I read in Brandon Turner's Managing Rental Properties that most banks do not loan on properties owned by LLCs. 

You'll also need a solid property manager who can rent the property out quickly once it's ready to go so you can get some tenants in there and maximize the value. 

Out of the eight units I own and manage, I have had countless tenants choose our properties due to in-unit washer/dryer.

I didn't have the time to fix and flip, or buy one single family home per year, and try to manage it.Two big differences between SFH and Multifamily.

Sure, about one in 2000 times, by someone experienced enough to recognize a very unusual situation, having the capacity to act on it, having the financial strength, experience and tract record to be able to attract the needed capital, having the knowledge and ability to structure the deal, having the ability to manage and or reposition the property after purchase, and having the capacity to carry the negative cash flow until turning the property around or obtaining lower cost financing.  

It's possible the deceased father agreed to let her manage the property and keep the rent net for her troubles, but the title/ownership remains in him so his heirs would inherit it as a legacy.I suggest your friend familiarize himself with the statute of frauds which I believe requires agreements regarding real estate be in writing to be enforceable.

It's important to take your time with tenant screening and be prepared to manage the property yourself.

For 15 years you manage to save up $20k per year and you have the missing $300k to pay $400k in cash.

I thought it was incredibly hypocritical when I worked for a bank and got those requests from "risk management".

You are a beginner in REI – so get started first, accumulate some equity, get some serious cashflow going, get some experience with managing real estate, figure out you want to do this long term…and then worry about how to layer an LLC cake.