I am a US citizen and my wife is a Permanent Resident at the moment. She isn't eligible to start her naturalization process for another few months. Her family is from Guadalajara and she has a sister that lives in Monterrey, Mexico.
Recently, her dad passed away, leaving only her mom in Guadalajara. Since we live in San Antonio, it is very easy for her mom to visit her sister in Monterrey and then stay with us in San Antonio for a while (4-5 hours on the bus).
Her mom has a tourist Visa and gets an I-94 every time she comes here. I've looked for this information...but I'm having a hard time locating what I need::::

I know that she has a 6 month limit on the time that she can stay here...then she needs to cross over into Mexico.
How long does she need to stay in Mexico before she can come visit again? Also, if she stays say for 2 months here..then goes back to Mexico for a short time and returns...does that mean that she is eligible to only stay for 4 months... or does the clock reset every time? Is it a certain amount of months in a calendar year? How does it work?

If anyone knows this info, or can point me to the right place.....I'd really appreciate it. We want to follow the law in every way possible.
Thanks in advance!

Phil + Luz

I don't think there is a written rule on how long she should stay in her home country before going back to the U.S., the general rule is that she should not be staying in the U.S. longer than she is living in her own country for the last year. i.e. she visited 3 times last year and stayed 3 months each time (total of 9 months in the U.S.) and lived in Mexico only for 3 months, the CBP officer might give her a hard time if this happens.

Always keep in mind that the tourist visa is to visit only and can not be used to "live" in the U.S.

Thanks for the response. Ever since her husband (my father in law) passed away...she's been bouncing back and forth between our house in San Antonio and my sister in laws in Monterrey, Mexico. We're just worried that they might deny her entry at the border one of these times. She's 62, retired and owns 2 homes outright in Mexico...so it's not like she's coming here desperate to work. I'm quite surprised that there are no written guidelines...or a set rule.

Anyone with anything to add?