My concern is that other than the pursuit of drama, there wasn't a need for Hanners to nurse her grudge/anger, carry that across states, force a disruption of business and then use offensive physical force (even if relatively slight) against her mother.
Consider what the scenario would have been if her mother had hit the desk awkwardly, hurting her back, or clipping it and taking a fall and striking a table or something. Suddenly all that stuff Hanners did becomes way more damaging to her case. Alternately, flip the scenario, if Hanners had cut mom out her life over the phone, and her mom traveled to her, yelled at her and then shoved her...is it ok because its Hanners but totally f-u to mom if she had done that same scenario to Hanners?
The problem is that in the scenario, Hanners is the aggressor. No self defense here, shes not under current or imminent fear of harm, she took her anger and outrage, and used it against someone. Intent? Not clear, but again, from an external view you could go, "Huh, traveling on a plane for the purposes of breaking into your mother's office seems kind of focused intent." Sure she feels justified. I'm sure someone that lost their home to a bank feels justified in barging into a bank and demanding to see the manager and then forcing their way into their office. But it doesn't make it the right way to do it.
She could have let her mom finish, based on the text mom had like...4 words left. But Hanners felt she needed to physically establish dominance and stun her mom with fear. She could have done her same speech, even with the finger touch at the end and it would have been fine. Instead she wanted to make absolutely sure her mom couldn't interrupt her, so she chose force.
I'm not saying Hanners should get arrested, and yeah, realistically unless mom is a super dick, no charges are going to be filed. But that shouldn't negate the consequences of the choice Hanners used to use force to punctuate her point.
But for those thinking this approach was right, ask yourself, how is this any different from shoving your girlfriend or slapping her to make her shut up so you can yell at her? Just because it is between two family members doesn't make it any less worse.