Second extension for my mom needed?

Please help me !

My mom arrived to USA on Oct 18, 2020 for my delivery. Due to covid situation, I applied for full 6 months extension till Oct 18, 2021 (online) for my mother in April. Then, in July, I see the status updated: biometric appointment has been scheduled and the appointment notice is sent. It also said that if the document is not received by Aug 29, then report it. So I was waiting for the document to arrive but it never did. And, I didn’t know that we should check the documents tab online that time! By the time I checked it was too late, as the appointment was scheduled on Aug 20 and we missed it!

Later, I managed to get in touch with USCIS and got a call back from immigration officer who rescheduled the appointment and said I will receive the document in 2-4 weeks! I haven’t received the mail yet but when I checked online, I do see that the rescheduled appointment notice uploaded. The appointment is scheduled on Oct 18 which marks the last day of her stay as per her 6 month extension period!

Now, I am worried that if she can give biometrics and stay until the decision is made by USCIS? Is that legal? How long can she stay? What is the next steps after biometrics usually?! And, I asked the immigration officer if I can apply for another extension, he said I won’t be able to apply for another extension as this one is still pending! So what can I do now??? Any expert advice on next steps?! Has anyone faced this?!

Thank you in advance!

You can apply for another B1/B2 extension and you should apply as per my opinion since the time you requested earlier is ending.