Side Story: Emerald Greengrass

                                    

                                          
Emerald had been a young commoner when it happened. She was about ten when her mother got sick. It started with simple coughs, and by the end, she was almost completely immobile.
Things like medicine didn't cure her. Instead, it only seemed to slow it down. And not by much. With a younger sister to provide for, Emerald took up the role as the head of the household.
She devoted herself to working, and was barely scraping by. Until she saw her. Queen Moon. She'd been passing through the village. Emerald barely managed to get her attention and plead for her aid.
Queen Moon showed sympathy towards the young girl. She saw herself in Emerald. She'd lost her own mother a few years ago, and was forced to take take on many responsibilities.
So she visited Emerald's house for a brief moment and helped heal Emerald's mother. It wouldn't get rid of the sickness completely, but she'd be able to move again.
And ever since then, Emerald had felt a great sense of loyalty to the Butterflies. So she trained hard and eventually became a maid in the castle.
Of course, she spent a few years working in the lower floors. But eventually, she moved up and was working with the royal family themselves. One of her only friends in the castle was Ivory.
Ivory had been quiet but kind. But ever since Prince Aster's coronation, she'd been...different. She'd been more outspoken, more lively.
She also knew things that sounded like borderline magic. Something called 'science.' Emerald managed to get Ivory to tell her more. And when she learned it was from Earth, a more advanced dimension, she began to plead for Ivory to teach her.
She'd hoped this new magic could help her cure her mother once and for all, and provide a better life for her family. Ivory was hesitant. It was not knowledge she learned on her own, and not something for her to give. So she asked Prince Aster, and he agreed on the condition that she swear a magic oath to never betray him in any way, or use this knowledge for malicious purposes.
She agreed, and so her studies began. She began with simple books on Earth Science. Then to more advanced sciences. And the thing that piqued her interest the most was medicine and anatomy.
While it would take years for her to learn it all, she could improvise. With Aster's books on alchemy, and the books on magical herbology from Mewni, she was able to begin experimenting.
First she began with small animals. She didn't want to hurt anyone, after all. She simply tried to change their color. And after a few accidents, such as causing them to accidentally change into some other animal or shrink down, she succeeded.
This first success would lead her to explore more about alchemy. She learned it could not only be used to change one thing to another, but also to heal using potions and brews.
She spent months experimenting. This became one of her main passions. Of course, she couldn't abandon her duties as a maid. So she mixed the two!
She created potions that could explode into soap bubbles, or clean clothing with a few dips into a blue liquid. Sometimes it would land her in a bit of trouble, but Prince Aster or Ivory would cover for her.
With a bit of tweaking, she was able to start making the first successful batches of healing potions. These were specifically attuned to her mother's disease, and thanks to Aster helping her acquire the necessary ingredients, her mother was making a quick recovery.
When she told Ivory, she was called in for a meeting with Aster. Rather than being angry, he was happy! He wanted her to continue her work, and write a book on all her research.
Not only that, but he wished to begin selling the healing potions on a small scale to the common folk. Things such as plagues weren't uncommon, and he wanted to put an end to it.
All the money gained from selling the healing potions would go right back into production. And they'd sell three different types of healing potions.
Low Grade Healing Potions, for weak sicknesses or injuries such as bleeding or a colds
Medium Grade Healing Potions, for moderate sicknesses and injuries such as broken bones and sicknesses like the one Emerald's mother has
High Grade Healing Potions, made using the best of the best ingredients to cure the most extreme sicknesses and injuries. Obviously it wasn't an all-cure, but it was a huge help.
Aster also made a plan for those who couldn't pay for the higher grade potions. Labor!
They could paid off their debt by helping to prepare the ingredients for the potions. None of them would be able to figure out how to actually make the potions, since only Emerald knew that for now.
Eventually, Aster would want the business to expand and have Emerald train multiple medicinal alchemists for the kingdom. But for now, he was happy with her.
And with the blossoming business, she and her family were able to buy a nice house closer to Butterfly Castle.
She was also promoted to being Aster's 2nd personal maid! She couldn't be happier. She hoped nothing would take away everything she'd worked for.