Yvonne was a great host, very nice, giving me a lot of advices.
The place is very nice : an independant studio, with a kitchen, 2 beds, a bathroom. You can also access to the garden.
The place is not in the center of the city but you have a bus to go over there.
But I rather prefered to use one of the bikes of the B&B, for a very nice ride to the center, along the river (20 Min).
I really enjoyed staying at Yvonne's place, no hesitation if you look for a place to stay in Rotterdam