Translation
It's something she came into the match with - it happened in a previous match and worsened.
I don't know what the final diagnosis is, or whether they want to reveal what it is, but they were going to check it after the match.
Her dad wasn't very happy that she continued playing. But, hey - the apple doesn't fall far from the tree - she is stubborn because he is stubborn - that's the example he set, and she followed it!
Personally, I'm glad she continued and definitely made a match of it. This shows the other players that she's not going to just roll over - even if something is obviously wrong.