Extend tourist visa stay in USA due to coronavirus and waive I-539 fee

My mom has come to US on a tourist visa and her I-94 expires on the first week of May.

Due to the coronavirus, travel restrictions have been imposed in our home country (India). Also we want to avoid the risk of traveling in flights at this time.

Is there an easy way to to extend her stay in the US by one or two months?

I am aware that we should fill out an I-539 to extend our stay. But in-order to submit the online application it requires a fee of $370.

1. Is filing I-539 the easiest way to extend her stay at this time?

2. If so, is it possible to waive the fee due to the coronavirus situation?

3. After filing I-539 should she wait for an approval to continue her stay? Or is the receipt good enough?

Can you please help me with these? Thanks!

[Edit 1]: With the current situation of the virus, traveling anywhere sounds like a very risky operation, especially for elders.

That is the main reason behind this question. If the US government will allow visitors to overstay until Covid-19 settles down!