There is a girl i work with (no advice on i shouldn't even consider her because it will fuck up work please.....)
We get on well, and flirt, light kino... But she has a boyfriend, she hasn't told me about him and even when given the chance she avoids saying his name... I'm pretty sure she doesn't know that i know.

For example she knew something that happened at work (work in a bar) While she wasn't there, her boyfriend was in and was told about the incident.... I called her out on it and asked how she knew, i expected a response like " ***** told me" but she said " i just know" avoiding telling me about her bf...
I don't want to escalate too fast or do anything to rash to create an awkward SPAM.. How would you read this situation.?.?.

wait a few months to a year and then create the awkward SPAM.

Sounds like she's trying to get some attention.

Don't play into it, game other girls especially the girls that order drinks. Check her reactions and such then post back.