My daughter is almost 3 and still says “that’s mine” to everything

I know this phase is normal but it’s been going on for like close to a year now so it seems kind of long to be a phase.

It’s kind of embarrassing, like we’ll be at the park, and a kid will go on the swing, and she will run over and yell “that’s my swing!” Or “that’s my slide”. I feel like whenever we go to the park it’s just her running around telling everyone everything is hers. Same thing at the library in the playroom, or any play areas.

I tell her “no, the swing isn’t yours, it’s the parks swing and the park is sharing with you and all the other kids” it sounds stupid lol but I don’t know what else to say.

Then like the other day we dropped my son off at school and this women was getting in her car. My daughter yells to the woman, “NO, that’s MY car” luckily the woman didn’t hear her but like what the fuck!

Then earlier today we were at the supermarket. I put all the stuff on the belt and everytime the cashier scanned anything my daughter was like “hey that’s mine!!!”

I don’t know how to get it in her head not everything is hers. I am constantly correcting her bc like I don’t want people to hear her and think I am raising her to think everything belongs to her, like definitely not, but for some reason she thinks it does

So yeah, this has been going on for close to a year and I feel like it’s getting worse. What do I do?