My cousins age 20 and 17 got their work permits through the dream act passed in aug 2012. Question is their mom holds a green card can she file for them since they are un married and under 21? Also next question is once she files their I 130 they have to wait approx 3 years till their visa num is available. In the mean time can they still renew their work permits through the dream act in order to maintain their status ? Please advise

It can be done both ways. They are eligible to get work permit and renewal is possible. Form I-765 must be filed 90days before expiration date on the card.