How do you politely tell your kasambahay not to let your children watch the soap operas and trash television she loves to see?

You can set rules as soon as you hire them. Make it clear from the start that you allow your kids to watch certain programs only. You can even give her a list and the specific hours when your kids are allowed to watch, and tell her that aside from those TV programs, you no longer allow your kids to watch any other program.

I'll tell her while we're eating and joke her na "uy wag mo namang sanayin si ineng manood ng teleserye". Or, I'll tell her from the start before hiring her that I don't like my kids watching teleserye's because most of the soaps now are somehow not appropriate for children.

Day 1 with kasambahay is where i usually state the rules of the house and that includes no watching of soap operas and trash tv. That means i determine also which channels are okay for my kids. Buti na lang may phone sya na may tv.