I dont think she's really showing zero interest. Many others also dont think she's showing no interest.
She's showing very low interest. Even if she was very interested, why are you so obsessed over this one particular girl rather than the dozens of others you could approach with far less effort who are just as interesting if not more so?
Approaching these girls will also cause her to peak her interest level and go for you too, because she'll get jealous and intrigued that you're attractive to these other women.
You can p*ss about trying to extrapolate interest from tiny looks and glances and speech patterns and whether she accidentally breathed on your arm once.
I did it for years. If you're very lucky all this obsession might succeed in getting you lucky, if her self-esteem is unusually poor. But
99% of the time all it will lead to is you becoming a sap, chasing this one girl around as a beta orbiter while she treats you like a gay best friend begging her to f*** you.
If I've learned anything from dating in the last year, it's that
none of it means anything unless she's in your bed naked enthusiastically offering to bounce on your ding-a-ling. Only if a girl is to the point of begging for you to slam her silly do you know 100% sure that she's really interested in you. And even then, pretty often it doesn't mean an awful lot these days.
We have another guy in another thread who has slept with a woman and she's still "mid interest".
After sleeping with him.
So why are you so concerned that this woman occasionally shows the vaguest hints of finding you ever so slightly more interesting than paint drying?
Go find a hot girl who stares into your eyes, gets breathy and puts her legs all up against yours. Presses her t*ts into you when you're talking. Leans close to your face when you chat.
That's interest. Not some wimpy hints over months and months.