My mother-in-law had visited US tourist visa (sponsored by me) along with my family when I was in US. It’s almost more than 2 years we all returned back to India, however some reason my spouse cousin requesting my mother-in-law to visit US for their support. Can my mother-in-law visit US (in my / sponsor absence) base on cousin sponsorship letter. Do we need any other documents to show US immigration, to allow entry into US.