Is my girlfriend right to feel jealous about our female coworker?

Anonymous
Me, my girlfriend and this other woman ("Anna") are all coworkers.

Anna is old enough to be my mom (in fact she has a son my age, she was a teen mom). Yes she is good looking for her age. But I don't want her and I don't think she wants me. We never flirt with each other.

But my girlfriend is jealous because we are always having pretty deep private conversations. I feel like I can tell her anything and she tells me her problems/issues too. She is like the big sister I never had.

We started working together before my future girlfriend joined. My girlfriend thinks that if I have deep things to talk about I should talk to her not Anna. But she doesn't understand that a girlfriend is not like a sister, I want to be a strong man for my girlfriend.

By the way me and Anna are never together outside work (we don't even have each others numbers) and even though we have private talks at work we never go into a private room or anything like that. My mom is dead and I don't have a sister or any other female relative. Male friends just aren't the same

Is my girlfriend wrong to be jealous?
Is my girlfriend right to feel jealous about our female coworker?
4 Opinion