Grabbing a drink isn’t assault. Nor is it battery. It is, at most, petty theft.

Common misconception. You should read the legal definitions of both "assault" and "battery". I would guess that you're conflating the "aggravated" variants for the simple variants. Grabbing a glass from someone's hand does, actually, meet the criteria of simple assault and simple battery.

Assault: "Assault is generally defined under common law as an intentional act that puts another person in reasonable apprehension of imminent harmful or offensive contact. No physical injury is required, but the actor must have intended to cause a harmful or offensive contact with the victim and the victim must have thereby been put in immediate apprehension of such contact."

Battery: "Battery is the intentional infliction of harmful or offensive physical contact with another person without consent."

Basically, "assault" is merely making someone think you're going to touch them without consent, and "battery" is merely touching someone without consent. Grabbing the drink meets the legal definitions of both. Throwing a drink on someone also meets the definition of both.

"Petty theft" (Petty Larceny) applies to simply taking something without consent. When any level of force is used against a person in the process of the taking, it is not "theft" or "larceny". It is "robbery". The use of force in the taking is the defining difference between theft/larceny and robbery.

Whether her intention was assault and battery or robbery, she initiated the physical altercation. He might not have been justified in throwing the liquid at her, but she certainly provoked that response with unjustifiable use of force.

I stand by my analysis. She committed simple assault and battery in #1.

#1 might not justify #2. He might get charges of disorderly conduct for #2.

#2 certainly does not justify #3. She committed assault and battery in #3. Simple or aggravated is an open question.

#3 certainly justified #4.

#5 might not have been justified. It's an open question.

#7 was not justified.

#7 justified #8.