Accessible evnts in DC

Wow -- first post in here!?

My folks are coming to town, but unfortunately one of them will be wheelchair bound mostly.

The smithsonian museums are great, but will be challenging to navigate (have done before with wheelchair)

Any more accessible things to do? Also, bonus if they are toddler enjoyable envents. Im thinking maybe Brookside gardens.

Also, a side note: if you have younger kids-- the Dr. Suess event at Tysons Galleria is great!!