Hi, We were in Baltimore. Friends suggested The Sleep Inn 6055 Belle Grove Rd. phone (410) 789-7223 and/or The Comfort Inn 6921 Baltimore- Annapolis Blvd. They are off 695's exit 6A .
There is a nice place to eat that welcomes children. It is called Rose's Rest. Good prices,etc.
There is Amtrak within walking distance of the hotels. Amtrak also has a free parking lot there. One way ticket for one adult is $0.90 from an easy to use machine.We traveled to Camden Yards. A 3 block walk to the Inner Harbor. Or you can ride the bus or take a taxi into the Harbor. This saves the parking garage fees.
If you call the hotels I am sure they will let you know how to keep the baby's milk refridgerated. Have you thought of using POWDERED FORMULA and bottled water while you travel. I did that years ago and it worked nicely. I did not need the refridgerator fee added to the room rates.
I hope you have a nice trip....