Minor child social security benefits

My minor daughter started receiving a social security benefit when I retired and I started collecting my social security benefit . This year she earned  $12,481.00 from social security. She has no other income.

1)Does she need to file a tax return?

2) If so, can she file a separate return from mine(ours)? (My wife and I file jointly)

3)If so, what form should she use?