Hello again!
I've always had this OC with me, but haven't had the time or chance to make a full reference sheet for her...

She is Emerald Heart, a Unicorn born in Canterlot with a talent for Goldsmith and jewelry. She likes to research on jewels and fashion, and also spent time with her step sister and friends.
She was raised by her father due to her mother passing away when she was just a little filly. But in her late years as an infant, she would get a step sister in her best friend, Flammy Valeria, who was adopted by Emerald's father after finding out that her parents couldn't provide for her.

Despite her being as tall as Princess Cadence or Sassy Saddles, she is rather benevolent with her mood, presenting herself as gentle, humble and polite mare. While she had a hard time with bullies and conflict during her childhood, she would not hesitate to step in when needed or forced to do so.

Her collar is made of three Plaques of Silver, Rubies and three Emeralds, which were given to her by her mother.
She is often seen in her workshop developing new ideas and designs for her shop or also going out in the fields to find rare jewels and other precious stones. But she is obsessed with details thanks to her craft, which can make her over focus and miss the rest of the picture at times.