Normal or not? Toddler tantrums

My daughter turned 2 a couple months ago. I know the term “terrible twos” and I know she’s going to have tantrums. But sometimes I worry she’s either a huge drama queen, or she’s really not good at regulating her emotions. She freaks out and screams high pitched when I brush her teeth, sometimes when she doesn’t get her way she’ll throw herself on the floor, throw something (whatever’s in her reach), tries to pull her shirt off and scratches herself in the process (as if she has all this emotion and doesn’t know how to get it out, so she has to do something with her hands) it’s not like this all the time, most of the time she’s really good and sweet. Her vocabulary is advanced so it’s not a communication barrier. The problem is my SIL tells me there’s something wrong with her and she needs help because she witnesses these tantrums sometimes. Her 4 year old does the same (but he’s autistic) and her 2 year old does sometimes but not nearly as much as my daughter does, or her daughter will just sit there and cry where my daughter will scratch herself and scream so loud. To be fair, my daughter usually gets like this when another kid is taking her stuff out of her hand, if she’s been in the car for like over an hour, if she’s hungry or thirsty or overtired. So there’s a trigger that starts it, it’s not like I just say “no honey don’t do that” and she loses her shit. But I get blamed for making her a spoiled brat. I would love to hear any stories of your toddlers if they act similarly sometimes because I truly think it’s normal, but I don’t want to overlook anything.