She stims a lot, constantly rotating her feet and wrists is totally normal. That's in my red book (for my oldest, who's a young adult) as a developmental level and she's right on target for it. I've nannied various babies and had 3 of my own and they've all done it and only one is autistic-and that high functioning.
She may be autistic, but there isn't anything that screams it to me, and she's very young for a diagnosis. Not saying no child will be diagnosed at that age, but it's relatively unusual. The only thing I'd watch is the not pointing, but she still has time to develop it. (suggested age is 8-14 months)
Every development for a child has a range, and some children are on the later side. It can also depend on what people use as the measure of what their child does. So for example, one parent might say they're sitting when they can do 2-3 wobbly seconds; another might not say they're sitting until they can sit without falling backwards in a couple of hours.
One of mine was late to do everything physical, but when she did it, she did it perfectly. So she took her first steps at 16 months, and two days later walked everywhere and never crawled again.
I totally get that you're worried, but I can also see why doctors aren't. There is a genetic element to autism, but it's not a guarantee.
How does she interact when she's with you? If you get say a toy where you press the button to make a noise, if you do it, will she imitate? Does she "share" things with you by holding it out to you, or catching your eye.
It may be that you have seen more than you've written that makes you worried, and I can't tell that, but also remember that if she is autistic, then she's still the same gorgeous baby that came out of you. Her being autistic will only be part of her. Play with her, cuddle her, and maybe she'll surprise you with her amazingness, whether she is autistic or not.