Okay so let me start by saying I work at a gym, and this girl is becoming a regular. I see her occasionally but never say much besides hey, or have a good day. I feel weird since I actually work at the gym, but I was just wondering of an approach. I think she is about 2 years older than me, and sometimes I catch her glimpsing over. She is always friendly when we do actually have small talk but that may possibly be her personality. Anyways thanks in advance

You shouldn't because are actually in a better position to approach than a guy who just works-out there. I assume your a PT?
She gave you the IOI's by smiling so I'd assume she likes you and walk right up when she's doing the dumbells or something and say "Thats good but you need to bend your wrists more like this" then take her arm and show her (Good KINO)
Be playful and tease her when she does it wrong again etc.

That's just an example but you want to do something like that. You say she goes regular so theres no rush to close, just play it cool and build up rapport over the weeks first then go for the number. I'd also suggest simultaneously run the exact same game on as many girls in your gym as you can that way you won't get ONEITIS and you will have natural abundance.

Thanks for the advice, it's kinda weird because she comes in at such sparatic times it is hard to know when I will see her next. Anyways like you said no rush, hopefully something will come from it.