A weight of ~0.8-1.0 is recommended (You might want to adjust the weight depending on your model). Feel free to experiment with other weights and share your results if you want to!
The main prompt is "MiriamHildegardVonGropius". Use "very long hair, twintails, hair bow" for her hairstyle.
For her outfit try the following prompt: "MiriamHildegardVonGropius, very long hair, twintails, hair bow, yurigaoka girls academy school uniform, black thighhighs"
Let me know if you have any issues.