B2 visa extension pending - How long can we stay in US after i94 expiry?

Hello anil,
I applied for b2 visa extension for my mom on May 6th. I haven’t received any biometric appointment yet. Her i94 ends on june 30. How long can she stay in US here? I have read in uscis for 240 days but everywhere they are talking about employment. Can you please confirm how long she can stay before receiving any approval information. Also how long after approval/ denial.

She can stay as long as the B1/B2 extension is pending or till the end date requested in the B2 extension application.

You may need to file another B2 extension if the current application is pending and the current extension request’s end date is approaching.