My sister-in-law is Mexican and lives in a border town. She is 65, retired, never been married, has her own simple apartment, a few thousand in a savings acct and receives a small social security monthly benefit. She has never had a US visa or been in the US. What will she have to have and show to qualify for a B visa for visits to our house and occasional border crossings for shopping etc ? Not much immigration info out there on older retired people. Are any of these policies changing under the new administration? Thanks!