Sorry this happened 
But at the same time, if a permit is required or chickens are just outright illegal, then I would get the appropriate permits rather than keeping them illegally or trying to get around the law.
Also, whoever adopts her would likely get in trouble giving them back to you. They usually have to sign a contract the animal is to be returned to them jot rehomed.
And also they usually check to make sure you have other chickens and appropriate housing, etc. They wouldn't just give a chicken to somebody with no appropriate set up, no other chickens, no permit, etc. They thoroughly check all that so that the animal has a good home.
Now that said, it seems odd and maybe illegal to just take her? Especially putting her up for adoption right away.
I would refuse to sign anything and get a lawyer or the news involved.
But if chickens really are illegal then maybe not because you're not supposed to have them.
But even so, it seems very very odd that they would just try to force you to sign her over immediately rather than offering to help you get the appropriate permits so you can get her back?
So I would get someone else involved or ask them to help you get the permits. Don't sign her over.
But also, it seems like you might need to clip your chickens wings or better contain your chickens so that they don't escape again.

But at the same time, if a permit is required or chickens are just outright illegal, then I would get the appropriate permits rather than keeping them illegally or trying to get around the law.
Also, whoever adopts her would likely get in trouble giving them back to you. They usually have to sign a contract the animal is to be returned to them jot rehomed.
And also they usually check to make sure you have other chickens and appropriate housing, etc. They wouldn't just give a chicken to somebody with no appropriate set up, no other chickens, no permit, etc. They thoroughly check all that so that the animal has a good home.
Now that said, it seems odd and maybe illegal to just take her? Especially putting her up for adoption right away.
I would refuse to sign anything and get a lawyer or the news involved.
But if chickens really are illegal then maybe not because you're not supposed to have them.
But even so, it seems very very odd that they would just try to force you to sign her over immediately rather than offering to help you get the appropriate permits so you can get her back?
So I would get someone else involved or ask them to help you get the permits. Don't sign her over.
But also, it seems like you might need to clip your chickens wings or better contain your chickens so that they don't escape again.