Help! I'm Tawanese In this sentence "Sonia should have been home by now, do you think she's ok ." Does Sonia at home? Thank very much?

No, Sonia is not at home. "Should have + verb+ is used with something that DIDN'T happen.

I should have gone to the dentist last week. (I didn't go)
He should have called me by now (he didn't call).

no sonia is expected and has failed to be home."should have" always means something that is not done, but was expected to be done. In this case it states the reason for the question."do you think she is OK ?