Jacky
Jacky is the latest Super Rare to be added to the game (which isn't saying much. She was added like, over a year ago) and probably has one of the more unique functions. She's one of five characters who can use a basic attack to directly hit someone when there's a wall between them. (The other four are the three Throwers and Mr. P, who is essentially a combination of Sharpshooter and Thrower.) For her main attack, she uses her jackhammer to pound the ground, which causes a tremor in a circle around her. This makes her really tricky, because you have to be careful not only when approaching a bush, but when approaching a wall with a bush on the opposite side. Her Super isn't very useful in many situations. It draws any opponents in a wide radius towards her and gives her a temporary shield, but it can be so hard to time and the shield lasts so little that it's not incredibly useful.
Jacky has no confirmed relationship with other Brawlers, other than being a part of the Miner Trio with Carl and Dynamike.
In the Starr Park Trailer, as the spokesman is riding a minecart through a tunnel, you can see construction workers all around. One is a woman with black hair like Jacky's and she's using an oversized jackhammer. This was probably Jacky, and she was probably on the construction/demolition crew before Brawl Stars.
Next we head for the first Epic character, Piper, the prim and proper snappy sniper!