Does my straight married colleage like me? Or is she harrasing me?

Weird situation with my straight coworker. My straight coworker (35f) has been super weird with me (24f) for about a year. I have worked with this woman for a year now. She is extremely distant from every employee except from me. She says she 'Hates everyone' but not, that she enjoys working with me rather than anyone else, and that she wished we had more than 8 hours to see eachother. We had a maintenence man come in once and I said he was flirting with me and she got angry and then jokingly said she was the 'only person allowed to' flirt with me. My other colleagues have noticed that she will come and see me when I clock in, and she will never ask about anyone else's day or make time to chat with any other colleages.

We work in different departments, so there is no need for her to do this. She asks my colleages where I am on my days off and she memorises my rota to the point she knows when our shifts and days off align. Even my other colleages find it weird.

I have a girlfriend, who is fully aware of the situation and is not bothered by my colleagues behaviour. It's more of a joke to us than anything else. However my gf often visits me at my workplace and this woman says to me that my gf should 'leave me alone' and that she shouldn't see me at work. My colleage complains about her boyfriend to me and says that my gf is very similar. She also makes comments about my girlfriend 'Tracking' me

At a work party she put her hands around my waist and (she doesnt drink so was sober) and after asked my colleagues the day after the party if I knew she 'wasnt gay' and never mentioned it to my face.

Another thing is that my girlfriend made a comment that I liked this coworker and she then ignored me every day (playfully) as she said she didn't want my girl friend to get Jealous.

I have no idea if she's actually into me, is having a gay awakening or just plain mean.