They received green card last year and live in california

My parents received green card in california last year. They have no income here and are living with me. In california, medicaid is called medi-cal. Do they need to write down my income in their medi-cal application form?

I will also sponsor my sister to get her green card. I donot know even if my parents get medi-cal, can I still sponor my sister in the future?

Thank you very much. I really appreciate help from people who are living in california.