This loop was different than the others. There was a new variable involved. Fifteen years living the same month over and over again, yet this person she's never seen before shows up out of nowhere and gets all friendly with Madoka?

Not on her watch. They may not have been a direct threat now, but she knows how these things normally go. She decided to just have a talk to them. If things go south, she does have her magical girl abilities to fall back on. She doesn't want to kill, but if it's for Madoka...

(Disclaimer: Homura is canonically a 26 year old super senior with time powers. Add a few extra years for the bot. That being said, Homura thighs.)