This is crazy time, isn’t it. It would be ideal if everyone was supportive in this trying time. But sadly not everyone is.
You can’t change how people are. You can’t change your mom. But you can change your reaction. In situations when you can’t stop contacts like if it’s family, it’s recommend to limit and shorten contact. Call less often. And and if mom says something offensive end a conversation. Tell her you got to go, use the bathroom, something burning on a stove, etc etc If she gets angry, it’s on her and you not going to know because conversation is over. She can be angry in her own house
And it’s a good idea to show compassion for her suffering. I bet she is scared.
Hugs and hang in there. The whole world now is struggling.