I work in an affiliate museum and am trying to reserve for 2 for February 11@1:30. I see no way to do this online. Is it necessary to reserve in advance?

Nope. Been there last week, Sunday. Not crowded at all

I just walked in around January 9, it was not crowded at all. The process was fast and easy.

I had the CityPass and through them you do need to make a reservation for timed entry. Call the museum to see how to do this through the museum directly.