Interesting question. I'm not sure what the legal and ethical ramifications for a tattoo artist are and good for you for having a line. Still, as a person who works with youth who have a variety of mental health and developmental disabilities I do think they deserve as normalized of an experience as possible. My instinct is that if the request was for something tasteful in terms of content and body placement it would be fine to go forward with it. I'll be curious to see what others say about this.