She was 8th in the Kanto regional competition iirc
totally forgot how recent was that though , whether it was in elementary/pre-h!P time or after
[edit]
whoops just checked the article, it mentioned she was 3rd in the breaststroke division for the Kanto regional tournament back in 5th grade. So pretty much before she got busy being an idol, I wonder how competitive/good she's actually now... being an athlete is hardly something you do on-off like.