I am a citizen of US. My mom entered US on tourist visa on 10June2010.
Applied for I-130 (family based green card) on 15July2010 and received receipt notice. I-130 is still under processing.

I am planning to file I-485 concurrently anytime now. Waiting on documentation.

My mom's I-94 expires on 09Dec2010.

I understand that i cannot extend my mom's visitor status beyond 09Dec2010 because of green card under processing.

For my mom to stay in US beyond 09Dec2010, is an I-485 application by itself sufficient or should i get advance parole or something else? Also how early should i apply for I-485, prior to 09Dec2010? Please advice.