You go talk to her after the match

After the matches for the day have concluded and everyone has dispersed, you decide to go looking for Millie as you were impressed by her ability and newfound strength. You wander around the palace until you eventually stumble upon Millie, sitting on a chair, resting and scrolling on her phone.

She looks up at you with a smile, friendly but with a hint of satisfaction. "Hey there. Still sore from earlier?" She asks in a playfully teasing tone.

"Oh, absolutely." You respond while rubbing your sides. "That squeeze was vicious, since when are your legs that strong?"

She laughs. "I have been bulking up ahead of the tournament." She says as she flexes her legs. "Look how thick they are now." She motions to her legs with a smile.

"Damn!" You exclaim. "No wonder they hurt so badly."

"Yeah." She responds with a chuckle. "All that training did wonders for my strength too. Honestly, i'm considering keeping this up even after the tournament. I have been really enjoying working out and i like my legs like this." She pats her thighs.

"You should! The power looks great on you." You can't help but praise her legs, eliciting a proud smile from her.