If you are at least 21 years old, you can apply for your mother's papers immediately. But in order to know the exact process, I will need to know more about your mother's history. Did she enter the US with a visa? If she entered illegally, did your father file papers for her before April 30, 2001? Your should be prepared to provide these details to any immigration attorney you contact. Let me know if I can help.
If you are over 21 you can petition for her and yes it would be faster. You also need to speak with an attorney to determine if there would be any problems with her petition. For a free consultation give me a call.
716 830 7960