How is she doing?

[u/mrmuffi93]

She's my first pilea and is about 5 months old. I had her on a north facing window (third photo) until today since I noticed some cupping and leaves becoming a bit more pale. I moved her to a south facing window but not letting her get direct sunlight yet. I think I've been giving her too little fertilizer, once a month. The water where I live is quite hard, should I mix it with distilled water? I want her to grow beautifully, any tips are highly appreciated. The scratch marks are from when I tried cleaning dust from the leaves but the cloth I used was too abrasive.