Originally Posted by
Aldoman
I think that in order to "reset" her stay your Grandma must hand in her I-94 slip when exiting the US at the border in TJ so when she returns to the U.S. she would need to get a new permit and a new stamp with another 6 months. If she doesn't hand in the slip, immigration at the border will see it and just let her in again without stamping her passport and the original entry date still running.
At Mexico border crossings, is there any US facility at which to hand away an I-94 form? I have walked across the border from TX before, and do not remember seeing any such facility. In fact, nobody was even watching the border from the Mexican side; we just walked right in. (I guess border security is not as heated a political topic in Mexico as it is here - at least re: the US border).