1girl - wha?

So, pretty much every sample prompt for animated/anime based stuff includes 1girl. I assume it's a Danbooru tag. I also assume that it's meant to tell the engine that there is going to be a single female.

Good, got it. Seems useful.

However, if I leave that tag in a pompt there is always a semi-specific girl with long brown hair and cat ears. It's kind of like I need to specifically overwhelm that character with more prompts to counter it.

Do other people have this same experience?

While I haven't encountered your specific problem, I've heard that some models/LoRAs/etc give specific and similar face results when using '1girl' in a prompt. I've also heard it recommended to nudge SD towards your wanted result via other prompting methods such as saying "woman" or describing her clothing, etc. Hopefully this helps.