It's up to you and your conscience. You say "our case: if you mean the criminal case, it is not technically your case. You are not a party, simply a witness. If she is deported or detained in an immigration jail, the prosecution may not be able to go forward with the prosecution.
You should repost this question in the immigration section.
I have been a criminal attorney in New York for almost 25 years. website: Brooklynlaw.net Phone #: 718-208-6094 email: email@example.com. This answer is only for informational purposes and is not meant as legal advice.
You can if you feel it is necessary.
Joseph A. Lo Piccolo, Esq.
Immediate Past President, Criminal Courts Bar Association 11'-12'
Hession Bekoff & Lo Piccolo
1103 Stewart Ave, Suite 200
Garden City, NY 11530
516-408-3666 (o) / 516-408-3833 (f)
I am a criminal defense attorney practicing in Nassau, Suffolk and New York City. The above information is not a substitution for a meeting whereas all potential legal issues can be discussed.