can my sister visit me on B2 while applied I-130 and its pending for my sister, my father and mother

[AllyZZZ]

Im a US citizen, applied I-130 and its pending for my sister, my father and mother.
She, her husband and two kids have B2 visa for the rest of the year.
They want to come visit me in US from Ukraine (Crimea, I guess its Russia now).
Is there chance that they would not be allowed to enter US? Or everything is fine?

Thank you very much!