Met someone at work, why does she behave giddy and childish?

I was introduced to her not to long ago. I’m not really one to go up to coworkers and talk to them and just strike up convos but people here do like interacting with me and I’m thinking about being more social.

Alright so here’s what happened, when I first met her she was chill and nice. Now she acts childish and giddy. Like she says my name in an excited and enthusiastic tone and smiles at me, there’s also waving. The best way I can describe it is she says my name in all caps out loud and with exclamation points.

Then I passed by her and her coworker. The other girl asked me if im going to a retirement party I said yeah. Then the girl this post was about said yeah you should come and smiled.

Nothing happened at it, I wasn’t really around them though. But then I was at a table where they were gambling and she was leaving. When she was leaving, she tapped me on the shoulder I turned around and she smiled and waved goodbye at me.

Idk if I’m overthinking. I know she’s comfortable around me and I actually wouldn’t mind just having her as a friend cause I like her personality.

She acted neutral before but now definitely acts warm and enthusiastic towards me.

Last thing was her friend suggested we hang outside of work before, and she agreed.

She’s also spoken highly about me of others. We don’t even know each other that well though tbh.