Microscopes and Magic by Andi C. Buchanan

Some magical problems take spells and potions to solve… but others can only be understood through the lenses of a microscope.
Marigold Nightfield’s life changed when she absorbed the magic stored in a family heirloom. Now, she’s part of a growing network of magic-working scientists who are trying to change the world for the better, and has a girlfriend from a sprawling, powerful, witchy family.
Things should be coming together perfectly for her… but her magic has a time limit. It’s not hers for keeps and one day, she’ll lose it for good.
When her girlfriend’s work is destroyed by possible sabotage, and strange things start appearing in Wellington’s green belt, Marigold’s amazing new life starts to unravel. With unknown motives and dubious players at work, she faces a destructive force spreading through the city and beyond. She’ll have to not only draw on her scientific background and magical abilities, but make new connections and grow in confidence to face this new threat.