Hi anon! Yes, it’s true that there are lots of stereotypes about autistic people, and that the stereotypes that are attributed to autistic women— shy, bookish, STEM majors who cut their hair short and ignore it and who never wear makeup and who choose comfortable clothing and practical shoes over fashion— are pretty limiting.
That’s why I think you should walk all over those stereotypes on the way to being yourself. If fashion, fabric, and clothing are your passions, go for it! Sure, ignorant people will be silly about it (“You’re autistic? But you’re so pretty!”, “I thought autistic people like math, or music?”, “But you seem so normal!”, “Do you like trains too, though?”) but the most important thing is being true to yourself and making joy out of your interests.
So keep your chin up and, and please don’t feel like you have to compromise on what you love for other people! If anyone gives you trouble, you can say, “Well, I am autistic, and this is what I like/do/look like, so this is what an autistic person likes/does/looks like!” and then go back to your clothing, because you are awesome, and fabric and colours are very beautiful and important.