<human>: This just happened today in the morning. The following is my mom's description of what happened. Unfortunately, I wasn't there to see this.

My mom was buying stuff from the store and paying the cashier. While on the phone, she realized she forgot something, so she reached over near the person behind her to grab it. 

The person behind her was a medium-build black lady, with a Louis Vuitton handbag, in her 30s. She shouted at her. The conversation went like this:

*Black Lady*: YOU SHOULD HAVE SAID EXCUSE ME! YOU'RE BEING RUDE!   
*Mom*: I was on the phone.   
*Black Lady*: YOU STILL SHOULD SAY EXCUSE ME!   

At this point, the black lady, with her palm outstretched, made this grabbing motion towards my mom's face. 

One of the cashiers at the store shook her head and said, "I'm sorry that you've had this experience here."

My mom left and proceeded to her car. The black lady followed her to the parking lot and screamed, saying "You want to say something now?!" She got really close to my mom and said, "I would beat you up if I didn't have to go somewhere right now!"

My mom said, "Go ahead, I'll call 911."

The lady mumbled something and got into her car (a Mercedes). While my mom is driving, the lady still follows her, passes her from the opposite lane, and suddenly hits the brakes. (With the intention that my mom would smash right into her)

My mom honked. After 20 seconds, the lady finally left. 

My mom was in tears when I saw her. What would you have done in this situation? We are thinking of purchasing pepper spray for self defense in the future. My mom says that the other lady would have gotten violent if there were any reason to.

Can you provide a brief overview of the text?
<bot>: A biggish black lady in her 30s nearly assaults my mom in broad daylight. My mom is in tears right now. What would you do?