Hello.
You can petition for your mother and your sister at the same time with seperate I-130 petitions. Your mother, as an immediate relative, will recieve her visa immediately as opposed to your sister, who, depending on her nationality, will take significantly longer.
Call me for a free consultation to further explain how and when your family can immigrate to the US.
Answered on Feb 11th, 2016 at 7:41 PM