elizabeth sedway , 51 , has rare plasma cancer and was returning to california with her husband and two children from hawaii vacation .
sedway shared video of her removal from alaska airlines flight on facebook .
she said airline representative took note of her because she was wearing a surgical mask and was sitting in handicapped section of boarding area .
sedway was told the airline was concerned she might collapse on the plane .
the cancer patient is expected to miss two chemotherapy sessions because of the delay caused by the airline .