Moving to Another State With Chronic Illness?

I am asking this question on behalf of my sister, who was diagnosed with colon cancer about 2 weeks ago. She has already applied for Obamacare and is paying her premiums. In addition, she started a new job (Nurse) about 2 months ago, which also came with private insurance. Unfortunately, she told them she had cancer and they fired her this morning – which they can do within 90 days from the start of employment. My question is this: She is all by herself in Florida, and will not be able to go through surgery and chemo without assistance. We would like her to come up to New York where family can take care of her. What is the process for moving her Obamacare insurance to the New York exchange? Will there be a gap of insurance? She has been told that she needs surgery ASAP. She is feeling overwhelmed, because she will not be able to keep her apartment and nobody is going to hire a nurse who has cancer. No job, and no income. Please provide any information you can offer, thanks.