So I've been doing Best Ending speed runs of this game and Anita has been giving me some trouble lately. So today I decided to dig into the game and figure out exactly how it works. Note that I haven't messed with recruiting her at Banner Village so this all applies to Muse.
So first off, each time you're in Muse she has 3 dialogues she can give you. She either asks for an Antitoxin, asks you to refill her drink, or gives you the "What is it? A Female Swordsman isn't so rare, is it?" dialogue. Once you get one of these, it won't reset unless one of three things happens.
1. You re-enter Muse.
2. A day passes. In this part of the game, this is when Jowy comes back & you wake up the next day to go to Jowston Hill.
3. You save & soft or hard reset.
So Anita works off a point system. I originally thought you needed 3 points to recruit her based off previous experience but I was a bit off. She actually needs 5 points. The tricky part is that how many points you get is dependent on what dialogue she gives you. Here's a list with the 3 dialogues she can give you and their corresponding points.
"What is it?"
Option 2: 2 points
Option 1 & 3: 1 point
Give her an Antitoxin: 2 points
Try to give her an Antitoxin but you don't have any: 1 point
Say "No way.": 0 points
Refill her drink: 1 point
I got 4 drink refill dialogues in 1 run and it took me forever to get her which prompted this investigation.
Also, once you get the recruitment dialogue, if you pick Option 3 it will subtract one point. So if you had 6 points and picked that option you can just talk to her again and she'll give you the option to recruit her again.
And for the more technically inclined, the memory address for Anita points is 0x00069815.