I94 xpire 05/05/2020. Foreign passport xpire 10/10/2020. Return flight is 04/02/2020. Applied for B2 extension for mum cos of virus fears. Good or bad

My mum is 60. Has a B2 visa, slated to travel back April 02,2020. But we are terrified due to the covid-19. We want yo reschedule the flight for August and have applied for i539 to extend her visa. Her foreign passport also expires in October 2020 so she is definitely going back before October. My question is, it seems she may not get either an approval for denial before she returns home in August going by USCIS timeline. If she returns before a decision. Would that affect future chances of B2 visa? She has history of visiting and returning back timely. Her current visa expires 04/10/2020.