3 months is far too early to pick up signs for autism. It’s probably just very overstimulating, or unsettling being in a different environment, is she in a pushchair, or on you? Can try baby wearing if that helps for comfort.
Oh my gosh, she’s 3 months. People don’t need to be mentioning ASC at this point. Babies get overwhelmed and overstimulated very easily. As she gets older I’m sure she’ll get more used to situations like that.
Try baby wearing her, she’s 3 months old it could be 28362 things and autism is the bottom of the list x
Try going during her naps so leave before she naps and hopefully she might sleep while you shop
My son is 4 months and was the same I’ve found if I turn the carry cot part of his pushchair into the seat and lower the hood so he can be nosey he now loves it also talking to him and making him laugh on the way round, what also worked is light up Halloween or Xmas toys I’d pick one up off the shelves and put it in front of him he’d be so focused on that he would calm right down then I’d always end up buying it because I didn’t have the heart to take it away from him lol
Could be the lighting. It's awful. I hate fluorescent lights, my son was the same, were now both diagnosed with autism 😅 not saying she defo has it. But generally fluorescent lights affect a lot of people with asd! Xx