I assume you are inquiring if it is faster to apply for your mother as a US citizen rather than as an LPR. Except to file petitions for spouses and children, US immigration law does not provide avenue for LPRs to file petitions for their parents. Only US citizens may file petitions for parents. So, if you wish to file for your parents, you must first apply for and become a US citizen yourself.
Answered on Jun 28th, 2013 at 3:53 PM