I stayed in Mary's smaller room with unattached bathroom for 6 months when I first moved to DC. It's a lovely neighborhood, a beautiful old home, and a great room - small, but it fit my needs. I didn't use the kitchenette a whole lot, but it was there when I needed it. Never ran into trouble with other guests. Mary was always very responsive, helpful, and kind and had great tips about the neighborhood.
The house is within walking distance of the eastern stretch of the H Street Corridor and all of the great bars and restaurants to be found there. I recommend Maketto (as will Mary!), Smith Commons, and the Copycat Co. For fast casual there is an &Pizza and a Cava fairly close by, and a Chik-Fil-A just up the street. The house is also a 20ish minute walk from Slo-Nickel Laundromat (although Mary was often willing to do a load of laundry for me). There's a 7-Eleven, a Whole Foods, and a Giant closer to Union that are easily accessible by foot or the free streetcar. For cheaper options you can walk east to the Aldis or Dollar Tree. There are several gyms close by as well.
In terms of public transit, there is a free streetcar that stops at H&13th and will take you to Union Station (5-10 minute ride). That was my standard commute. There are also plenty of bus stops around - I tended to hop on the X1/X2 at H&14th. The electric scooters are everywhere as well and can get you to Capitol Hill in less than 15 minutes - often the fastest option during morning rush hour.
Mary was always there as a resource. She mostly let me keep to myself, but was more than willing to help out whenever I needed it. All in all, Mary's place was a great home for me as I adjusted to DC life.