Marie is a terrific host. She was very flexible with our check-in times. We were coming in late (almost midnight), but we messaged her beforehand and she was very accommodating. She even made us tea when we arrived and chatted with us for awhile.
As for the location, the tram line and bakery are right across the street, so it's very easy to get a start to your day.
Throughout our entire stay, Marie ensured we had what we needed and that we were comfortable. She's very friendly and we were very glad we booked our stay with her. If we ever came back to Heidelberg, we wouldn't hesitate to book her place again.