How do i get ........?

ok i need to know how to get my moms van back because it got impounded during a arrest she wasn't involved in or knew about until it was too late. Her kids took the van with no permission and she has no money to pay to get it out and cant ride the city buss for the rest her life because she has a bad knee and when she walks on it to long she has sharp pain. But anyways is there any way she can get it back without having to worry how to pay for it being that she wasn't there when it did get impounded ? what should she do ?