Getting Health Insurance For Aunt

Hey everyone, wanted to see if I could get any thoughts or guidance. Currently living in Georgia (state). My cousin recently moved from another country to GA, got his green card, and has settled into a full-time nursing job with a state-affiliated hospital getting BCBS coverage. His mother (my aunt) recently moved here as well but is uninsured and does not work due to language barriers / physical limitations. My cousin does well for himself (makes $80K / year), but his health plan doesn’t allow for adding parents.

My aunt recently found a suspicious axillary mass and likely needs mammography / ultrasound imaging in addition to establishing care with an OB/GYN but in the absence of insurance, she would end up paying exorbitant fees. Due to my cousin’s income, she (as a part of his household) does not qualify for indigent care either. What would be the best way to go about getting health insurance coverage for her? I’ve heard about ACA Marketplace but apparently those have open enrollment starting in November?

Any help would be a godsend.