Just use the trigger tag "zste" along with "1girl". Her horns can be added with the custom tag "zhorns". Beyond that her collar is tagged as "spiked collar" and the maid outfit brooch as, well, "brooch".

Default outfit: 1girl, zste, solo, black leotard, center opening, shoulder armor, black elbow gloves, white pants, black boots, long sleeves, zhorns,

Due to the low amount of useable screencaps and most of the images showing Zest in her default outfit this LoRA took a lot of effort and tweaking to get to the point where it can reliably put her in outfits other than what's in the dataset. Still, it's not perfect - the default outfit has a tendency to sometimes bleed over, particularly the leotard. Use the relevant tag from above in negatives and/or lower the LoRA strength a bit to get rid of it.

I recommend DPM++ 2M Karras and LoRA at strength 0.8 for AOM2. NAI users will have better results with Euler A at the same strength.