Our hotel is located about two miles from the museum.
You can hop on the street car, that stops near the front of the hotel. Will drop you off about 2 blocks from the museum.
Not within walking distance, however if you do not wish to drive, the street car will let you off about a block away. Also one could spend all day at the museum, easy.
20 mins walking
7 minutes driving/Lyft
It's not within walking distance, but the trolley is available. You can purchase all day passes that allows you to make the trip inexpensively. And, the trolley ride can tour you around many parts of the city.
Get an answer from Hampton Inn New Orleans - St Charles Ave / Garden District staff and past guests.