Visitor visa extension question

[Usa558]

Hi all, I have a question regarding visitor visa extension. My parent's return flight after completing 6 month is on 12th aug 2013. I want them to stay another 2 months with us. I have just filed visa extension application for 2 months. I got delayed in applying soon. I know there is some minimum 45 day visa filing guideline.

I don't know if uscis can issue receipt notice this soon. Can my parents stay just on the basis of visa filing or they will need uscis receipt notice to stay? I have heard uscis takes long time to finalize their visa extension decision. Since I have applied visa extension only for 2 months. I was thinking should I go ahead and change their travel tickets? Can someone please guide us on the basis of their experiences? I am so confused right now. I also don't want them to stay unlawfully jeopardizing their next time visit.
Please help.

[peace999]

The problem with applying late is that the USCIS response will be delayed past her curent I-94 date.
She will be legal as long as she has the receipt of filing even if it is past the I-94 date.

No problems if it is an approval. But if it is a denial, she will be out of status technically and must leave ASAP
( in a few days).
That makes it tricky the next time she enters. The CBP computer will show an overstay. And the onus will be on her
to prove that she had an extension denial and left Asap. Now , if she cannot prove that ( lost extension denial letter)
or the officer determines that she did not depart soon enough, her visa could be cancelled and she sent back.

To avoid potential problems at entry next time, I suggest she leave now before her I-94 date.
It does not matter the extension app is pending. The only th ing is you will lose the application money.
But her visa will stay secure.

Also remember that long stays like 6 mo nths and frequent extensions everytime she comes, will have an adverse effect on her
visitor visa renewal ( if she has to).