Yes she does

"Um, Yes, actually. I wanted to talk about that, actually." Sakura replied, Rin looking very concerned.

"Shirou saw the Einzbern heir last night." Sakura went on as she grabbed the rest of the papers, stacking them before putting them down. "I know the grail war is starting. I'm no longer part of it of course..." Rin nodded, if she was Shirou's property, she obviously couldn't be used by the Matou's for their purposes. "But I can't let Shirou get wrapped up in this!" She says, drawing close to Rin's face. "I need to borrow the Tohsaka Ley line, I can't let him get involved in this.

"No!" Rin shouted back before quieting her voice and looking around. "The masters shouldn't hunt down uninvolved third parties, so you and Shirou should be safe as long as you don't engage!" Sakura was taken aback, the inner rage that Rin hadn't saved her from the Matou family surfacing for a brief moment, but she calmed herself, focusing on the task at hand.

"But Shirou-" She started, holding the felt marker up as she started, but Rin stepped back, eyes now gold. "You should really listen to her~. Now that you're not with the Matou's, you should be fully safe from this grail war." Her eyes returned to blue as her sister looked panicked. "Archer! why didn't you let me handle this?" "Because clearly she needed to know what was going on, and she already figured out I'm your servant! Great job with giving the Class away, Master." She engaged in an argument with her servant, eyes flashing between blue and gold. It wasn't until She felt the cold of the marker on her hand that she returned her focus to Sakura. Her purple haired sister had written on her left thigh, looking down at it, she was able to read it upside down.

Sakura Matou's

Suddenly realizing that Sakura owned their body, they focused and looked at their sister. "Sorry about using this body without permission, Sakura..." Rin apologized, but Sakura waved a hand dismissively. "It's okay, but If you really want to make it up to me, let me use the leyline underneath the family's mansion."

Rin nodded immediately. She still didn't want her sister entering the Grail war, but as her property she didn't really have much choice. "I'll leave the door unlocked. Is it all right if I scout for the Grail War tonight?"

"Of course!" Sakura nodded happily. "The only other rule for now is you have to be nice to Shirou."

Both Master and servant accepted this, so the two of them headed back upstairs as the lunch break ended.