First try to train a lora for this character.

There is no trigger word.
Works goof with low weights of https://civitai.com/models/1201086/stardew-valley-portrait-style-illustrious

I recommend having (pixel art) word at 1.0 weight, and around 0.9 for the lora itself.

Example prompt:
masterpiece, best quality, high quality, 1girl, sophia \(stardew valley\), pink hair, black choker, borderlines, overalls, white shirt, simple background, collarbone, (cute:1.1), pixel art

Note: dataset consists of only 2 images! (used data augmentation)