Baltimore is a much nicer city than it's reputation would suggest. Our Cincinnati relatives were pleasantly surprised when they spent a weekend in Baltimore for a family wedding. It wasn't at all what they expected. Just like Cinci or any U.S. city, there are areas of the city that are safer than others. I live about 60 miles west of Baltimore & was raised just outside of DC. Be aware that traffic is a major issue. You will want locate relatively close to the hospital. The hospital is close to the Orioles & Ravens stadiums - not far at all from the Inner Harbor. There is plenty of shopping & dining at the Inner Harbor. (ESPNZone; Cheesecake Factory, Phillips Seafood...) The Maryland Science Center is there. They recently had the Titanic exhibit - you'd need to verify it's still there. Also, the National Aquarium is at the Inner Harbor. They recently completed an Austrailian Rainforest addition. I haven't had a chance to get there since it just opened. If the weather is nice, you can take a water taxi around the Inner Harbor or even over to Little Italy - plenty of nice Italian restaurants there. If you like history, Fort McHenry is near by. This is where Francis Scott Key was inspired to write the Star Spangled Banner. I can't speak for the night life.
If you like sushi, we have found the best sushi at a stand in the Cross Street Market. It's not fancy but is few blocks from the MD Science Center at the intersection of Light St & E Cross St. We walk it from the Inner Harbor/Orioles Stadium - it's a bit of a hike but very doable even for our 10 & 11 yr old.
DC is about an hour south with all that it has to offer. We spent yesterday at the Hirshorn & the International Spy Museum. None of the Smithsonian museums charge admission.