B2 visitor visa extension for 2nd time

I had applied for My mother’s B2 visa extension (filed I539 online) in Apr 2020 due to the covid situation. However the status is still showing as received. The original i94 expired in May 2020. How long can my mother stay in US in this situation ? do I need to apply for another extension if the decision is not received by Dec ?
if I get the approval by then and I need to extend for 2nd time, will there be any challenges ? Experts Please suggest/help.

Did you get any response from USCID ?

I am also waiting after filing for my parents ? What to do if you don’t get any response even after 6 months of filing?

I understand from other forums that people who are in the same boat are applying for another extension nevertheless. I am thinking of doing the same. Lemme know if you get any insights from other sources.

Did you apply for another extension ? I did not get a response for my first extension yet… Let me know what you did ?

Am in the same boat too. Applied for the first extension for my mother and still in progress. Is it possible to apply for a second extension?