I'm pretty sure it's Rika-chan too ('Rita' in the 
US dub).  From the thing on her wrist, I'd hazard 
a guess that it's from Episode 63: Sakura, the 
Pool, & the Big Wave.  They all have ID bracelets 
in that ep because they take a trip to a water 
park (is it a mark of my insanity that I can 
actually pinpoint something like this?  *lol*  
Too many eps!  Too many...*swirly eyes*).

Annndd...confirmation *G*.  It's from the 
beginning of the ep, when Sakura is helping her 
swim across the pool.  She's rubbing the water out 
of her eyes ^_^.

Prettity gallery!

Talia