and she may not actually be a social worker. Social Work is a degree and a profession which requires licensure. Most CPS workers I knew didn't have a social work degree or license.
Can't answer the first question but can the second: The reason for taking the kids out be as a reward/payoff. "Timmy, if you let me X, I'll take you to BK". "Timmy, if you don't tell your mom, I'll take you to BK." The kicker to all this is that I'm a social worker and I've worked with kids.