My mother has valid 10 year tourist visa. However, on tourist visa, she can stay upto 6 months in US. I wanted to know that after 6 months, can she fly to Canada for a month to stay with her sister and then return to US after a month. What's the min time limit she has to be out of US in order to re-enter US? I'm having a small child and would like her to stay with me as much as possible.
It is unlikely she will receive another six months after visiting Canada. The rule of thumb is that she must spend more time outside USA than inside.