It is shown she has no name, however; it remains unknown as to why .
Émile battled against her using Janet. When she used Toxic, Duncan protected her by using Hydro Cannon. She fainted and he was able to catch her. He later names her Sapphira  (the reason is unknown, but maybe because he thought it was beautiful).
It is also shown that she doesn't like Stunfisk (the reason being that they are pesky) .
She was briefly commanded by Mac to help him catch his first Pokémon, a Stunfisk. He commanded her very well and he ended up catching the Stunfisk .
She also learnt a new attack under his command, Poison Jab .
The three months Émile was gone
It is unknown as to what during the three months, but it's possible he trained her well during that time, when she was used in chapter 70, it was seen that she knew more attacks than when she was first seen .