Marie is a very gracious host.
The house abuts I-5, but as it's below grade and there's a sound wall, freeway noise was not a problem during my stay. On the flip side, the location is very convenient for getting around northern L.A.
To get to the bathroom, you have to pass by the open kitchen and through the living room, but both were empty each time I crossed them. The shower is on the next floor. I didn't encounter anyone on the way to or from my morning shower.
The double bed is quite soft, but I slept soundly. As long as you don't require a firm bed, you should be OK.
There is a large TV in the living room that guests can use and Marie allows use of the modern kitchen, so the apartment offers unusual flexibility.
My stay was entirely pleasant.