Normal. And though it frustrates you, please try to get used to it, because she is only three; this phase can last up to and through kindergarten for some kids. It is not a big deal; she is working out for herself how she relates to other kids and how they relate to her. She is unused to others coming up to her and sticking a hat on her head, so she interprets it all as not liking the kid, when what she doesn't like is the kid's action. She wants to do what she wants to do, and so does another girl, who tells her "you can't be a princess."
Different kids process this stuff differently. Some kids would do this with tearful "they're mean to me" talk, and yours does it with "I don't like so and so" talk. Is your concern that she is being negative and thinking mostly in terms of "I don't like" as opposed to "I do like"? You can guide her a little by asking her, "Who do you like to play with" or more specificially - because young kids need specifics! -- "Who did you have fun playing with at preschool today?" or "Did you have art today at school? (Yes, mommy) What did you do? What was fun about the paints?" etc. Guide with some positive questions, in terms of what was fun, what did you like, etc. -- not just about other children but about activities.
Take care that you do not over-talk the whole "I don't like" discussions; it's easy to end up lecturing our kids (I know, been there) about "We don't say I don't like people" etc., but at times it is better to not comment and just direct her to talking about something she DID like about her day. Yes, we don't want our kids to be negative or down on others but at her age, over-talking this will give it more weight in her own mind.
You could ask the teacher privately if your child seems negative in other ways -- Does she say "I can't do it" when asked to try something new, even something small? Does she complain about things more than other children, in the teacher's observation? "I'm too hot, too cold, the mulch on the playground sticks into me, Sue was mean, Bobby won't give me the crayon" etc.? Ask the teacher to be frank with you and say you need the teacher's help as you're figuring out who your child is, right now, in the school setting. But also do not get too wound up if the teacher does say, yes, she tends to complain etc., because she is only three -- a lot will change. But keep an eye on her, do not over-talk or lecture, and redirect, redirect, redirect.
By the way, it's also VERY normal at this age for kids to do the whole "you can't play with me today" or "I am only playing with Sally today and can't play with you" stuff. That also can go on up to and into K. Again -- you need to be able to roll with it unless a particular child is really singling out your child. Then it could be a bit of bullying --but not all such talk is bullying, and parents sometimes overreact to it believing it is. The child who says one day, "I can't play with you, I only play with Sally today" could be rejecting Sally for your child the very next day. Fairly normal stuff, and you need to teach your child ways to deal with it -- walking away and playing with someone else.