I-94 extension for a Visitors visa holder

[cravik]

My mom has a 10 year multiple entry Visa, which is valid till July 2015. She came to US around mid June and her I-94 is valid till mid Dec 2014. I would like to request for I-94 extension by ~3 months.

After reading different forums, it seems that a good time to file for extension is almost after half of your stay is over (approx. mid Sep) and when you still have around 3 months to get the extension processed. Is this assumption correct ? and I am also wondering if this extension would have any adverse effect when she goes for a VISA renewal next year (after July 2015).

If we don't receive the extension approval by Dec, she will return back and there is no question of staying beyond the original I-94.

[peace999]

your assumption is correct, in fact one could apply after 2 months of stay is over. It takes 2-4 months for the processing;
highly variable, depending on the case load.

Your strategy is fine ; to leave before I-94 if the response is not received.

About its effect on the renewal; it will depend on how she used the visa in the past. If it is a once in a while extension; no problems.
If she has been staying in US 6 months every year for the past 9 years or has applied for an extension very often, I would avoid it this time.