Your mother cannot enter on visitor visa with an intent to apply for residency in the U.S.
This response is general in nature and cannot be construed as legal advice, given that not enough facts are known. Any comments offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship. If you would like additional information based on this response, please contact my office at 510 657 7665 or 415 902 0832 to schedule a consultation.
Apply for the green card as you wish. Your mother is an immediate relative so you can start the process any time. Entry as a visitor followed soon after by a petition and application for permanent residency may raise a potential issue of fraud. Hire an attorney to help.
The answer provided here is general in nature and does not take into account other factors that may need to be reviewed for a more precise answer. You should consult with an immigration attorney before taking any action. The answer here is not intended to create an attorney-client relationship.
As my colleagues have pointed out in detail the only appropriate way to petition you mother is visa consular processing. If she travels as a visitor with the intent to adjust status after here arrival (even a few months later) she will be violating immigration law.
Currently it only takes 8-12 months with the help of an attorney to bring a parent of a US citizen to the US to obtain a Green Card. Don't risk your mother's future by doing this on your own. The response you've seen from the other lawyers here should tell you that you are not looking at this process correctly and you will do well to work with someone that does this for a living.
Representing clients throughout the US and around the world: www.PogueImmigrationLaw.com (513) 549-4420. We cannot provide legal advice or recommendations unless you retain our law firm to represent you. No attorney/client relationship will begin until you sign a representation agreement and make a retainer payment to open a case with us. Any information found here is general in nature and should not be relied upon in individual cases.
If your mother has the intent to remain in the US and uses a visa such as visitor where she must have the intent to depart the US, this would be an improper use of the visitor visa. The proper way to proceed is to file the immigrant visa for your mom and bring her to the US as an immigrant.