Since this question was first written, my mother was a lawful permanent resident until the middle of this year, when she was successfully able to pass her civics test, so now she is a naturalised United States citizen!
My eldest uncle died earlier this summer, but he often cared for my younger uncle, who is unable to take care of himself. Our family got together to help come up with a plan.
Because of the COVID situation, it is not safe for anyone to travel, so they've arranged to have some of my relatives' friends look after him for a while. But at some point, we might have to consider bringing him here to the US.
What options does the United States Citizens and Immigration Services centre provide to help immigrants with developmental or intellectual disabilities who cannot take English language tests or the civic test in general for naturalisation? Furthermore, now that my mother is a citizen, can she sponsor her brother to come into the US? Somebody told us it'd be much more hassle than if he were to apply for a tourism visa. Additionally, the Mexican consulate told my mother yesterday that immigration status generally moves much more quickly for a spouse, parent, or child, but not for siblings, which can take up to twenty years. Can anyone confirm this and provide more details?