Disability Travel - Southwest Pre board for eldery parents

Recently, I have traveled with my parents when they fly. They are 70+ and have difficulty walking. They also want to be sure to sit together. I am ooking at Southwest because they are one of 2 airlines that fly nonstop on the route they need to travel. Is it relatively easy for them to get the blue pre board passes with Southwest?

Very easy. They need to approach a GATE agent (not counter agent where boarding passes are issued and luggage is checked). If they state they need to pre-board they will receive a blue plastic "sleeve" for the BPs. They need to sit in the pre-boarding area for the correct gate and listen for the pre-board announcement.

Thanks Dianne47

I thought it was easy, but was not sure. Should they still check in at 24 hours just in case?