15 gymnastics

That's how you have to count it. 
1 gymnastics - 2 gymnastics - 3 gymnastics- etc. 
Mimi reached 15 gymnastics this afternoon. 

That was very important to her. 

I had mixed feelings when she started doing gymnastics in earnest (as opposed to the 3 years she spent doing gymnastics in Newpark, where it was mostly about hungover, surly instructors in their late teens casting a distracted eye on a long queue of young ones messing around with very little gymnastic action of any kind...) 
In her new club, they take things seriously. Perhaps too seriously. I was a bit uneasy at the thought of nine hours weekly of gymnastics when she qualified for the competition squad. 
I had a very serious conversation with Mrs Raheny and Mimi, making it clear that I would not be pushing her to go to her three weekly sessions, that it had to be an enjoyable experience rather than a chore. 

But she enjoys the experience.
She really looks forward to her three sessions.
She loves the feel of the mats and the smell of chalk and sweat in the air. She looks up to the older girls. 
She loves the training.  
She loved the competition last weekend. 

And I'll approve of it for as long as she gets such a buzz from it. 

13 gymnastics - 14 gymnastics - 15 gymnastics! 

Well done my Mimiteen.