[SUSPICIOUS... but she is easily distracted by that smile because wow, that sure is her brother looking genuinely happy, she doesn't see that every day. She sure doesn't want to ruin that, so she'll just smile in return!]

It seems that we have. I hope we can go on helping each other, Yukimura-san.

[And her cheeks flush a little at the compliment.]

Oh no, um... It's simply a skill that you never really forget once you've picked it up... I think.