Meh, think of it like this. Older generations tend to not know technology all that well. Let her have her frustrations. And have a laugh inside about it.
Trust me, parents are like that sometimes. If she wants to believe those things she said, what's the harm in letting her? You know differently, and we both know that getting frustrated and feeding into the confrontational nature of your mother's angry lecture will only make things worse.
All of this is easier said than done.