Get mad at her

"Someone who will beat your ass!" You explode. She frowns. "That's no way to greet anyone!"

"I'm sorry, I didn't want to anger you..."

"That's too bad, because I've had it with you now! I'll make you pay for this."

"..."

She looks at you in silence for some seconds.

"Fine, we can be rivals then. Feel free to challenge me when you actually have a weapon. Right now, I have to finish my exercises."

She goes back to her training, leaving you annoyed and frustrated.

You lost 20 social drive.
Your rivalry with Nashillbyir has grown.
Your enmity with Nashillbyir has grown.