Huh. So I watched the video. It's not a copy of her product, it's just a product in the same category---book nooks--as hers (a category which existed before hers). She was even confused how to make and use it, as it's different to hers. It's kinda similar thematically, but a lot of that stuff is--"library in a stone castle" isn't exactly an idea she invented, and neither are the mirrors etc.
She's got 4M followers on YouTube and works in a very expensive looking studio. I think she's doing OK. She's not a little underdog here.