Can sister visit US while pending I-130?

[AllyZZZ]

Im a US citizen, applied I-130 and its pending for my sister.
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!

 

[Triple Citizen]

It is very much possible they can be denied entry at a US POE and returned on the first flight back. It is also very much possible that they will be granted entry as visitors with no issues.

Is there chance that they would not be allowed to enter US? Or everything is fine?

 

[AllyZZZ]

Thank you !!