Pls. help

[nbandireddy]

Hi- I have a unique situation. My sister got her green card last year and she and her husband & kids applied for re-entry permit as her husband had a 2 yrs project in Australia. She has 2 kids- one is a US citizen and the other one born in Australia but is an Indian citizen. Her relations with her husband have been strained that she went to india- she has been in India for about a year while her husband is in Australia. Her husband posseses hers and her kids green cards and re-entry permit and is refusing to give them to her.
She has 1-55 signed till april this year in her and kids passports. She want to come here.
What can she do to get her? Pls. help.