It is luddite.
There are several words - Technophobe meaning someone who is afraid of technological stuff, Luddite is a name for someone who rejects modern advances (the Luddites were a political movement during the industrial revolution who destroyed the new mechanical looms in the textile factories). Your sister sounds more like an anarcho- primitivist! ;o)
I am dying because I cannot think of just a similar word. I believe it is a word derived from a fictional peoples from classic literature. I thought it was leviathan but it's not because leviathan means giant or beast. Please help me sleep!
I'm not sure what the word you are looking for but I am interested to know how they waterproofed boots in the Civil War :)
Antitechnology(ist) is a word, primitivism... I'm really not sure what word it is that you are looking for, but let me know when you figure it out. I even looked for an antonym for technocrat.