I have a great townhouse next door to the Ballpark. It is in Navy Yard close to a ton of new restaurants, 2 blocks from the Metro and walking distance to the Mall/Capitol/Museums. There's a full bedroom available with a queen bed, a queen air mattress and a couch for sleeping. Tons of kitchen equipment available for your use. A cat normally lives in this house in case there are allergies.
Navy Yard is the fastest growing neighborhood in all of DC. In the past 2 years over 20 new restaurants have opened up. It's also by a river and parks so it's a great place to walk around.
There is a free parking lot behind the house. Additionally, the house is 2 blocks from the Navy Yard metro station (Green Line) and within 2 blocks of many bus options.