If your mother is abroad she will have to go through consular processing after approval of her I-130. This will involve dealing with the National Visa Center (NVC) and the appropriate American Embassy abroad.
I suggest you consult with an immigration attorney who can explain the process to you so you are aware of what will be required and the time frames involved. As there is much more to immigration than just completing forms you will fine the time and money well spent.
There are two separate procedures for a person to obtain residency. If the foreigner is in the United States, she will process under Adjustment of Status with Citizenship and Immigration Service. If she is abroad, she will process through Consular Processing with the Department of State. With either process, she will attend an interview.
Immigration forms sometimes seem as simple as sitting on a burro going down the Grand Canyon. And yes, filling out a form is very simple. However, like the burro that takes a misstep and ends up killing its rider, filling out applications incorrectly can lead to a great deal of time wasted, money misspent and needless heartache. I recommend you have an initial consultation with an Immigration Attorney who will answer questions about how to achieve your immigration goals as efficiently as possible. Best of luck.
I hope this answer is of benefit to you. If you desire a personal consultation, with legal advice geared to your personal circumstances (as opposed to the general information provided here), please contact my office.
Elizabeth R. Blandon