I am a naturalized US citizen. I am planning to file PR application for my mom (she is here with me). I also wish to file PR petition for my siblings. Which choice is faster for my sibling's application: (1) I file for them directly or (2) my mom files it after she gets her PR. Also, is it faster if I get a lawyer to help my mom for her application than I do it myself by sending materials to a local INS office. Thanks a lot for your help. P.S. my siblings have been merried.