Harry Potter idea,
Harriet Violet Potter is a certified child-genius, much to the annoyance of the Dursley's.
She was a tech-wiz of her age with the keen ability to fix, improve upon amd remake any device or gadget after either looking at the blueprints and manuals or taking the item(s) apart herself.
After entering the Wizarding World, Violet is stunned by the lack of technology, and even more so by the laws against muggle technology.
Finding a loophole in the law is pretty easy, and Violet takes full advantage of it.
After all, since technology being brought to the wizarding world was illegal, she would just have to hand make her own using wizarding items, and magic.
2010, Fem!Harry, TomxHarry, Ravenclaw Harry