I assume you haven't made contact with her in those three years. People change, and 3 yrs is a fucking lot of time. Give her a call, ask her out. For lunch or something. Reasonable people do this, there's nothing awkward or inappropriate about it.
Make sure you don't sound too serious, nor desperate. Just a casual "ey gal, how's it hangin'? Long time no see, let's meet up and catch up on shit". Nothing fancy. Don't ask her out for dinner, don't buy her flowers, etc. See how she's acting, try to see if she's changed.
If you two don't meet up, you'll feel those doubts about "half of you wanting" shit forever.
Make sure you don't sound too serious, nor desperate. Just a casual "ey gal, how's it hangin'? Long time no see, let's meet up and catch up on shit". Nothing fancy. Don't ask her out for dinner, don't buy her flowers, etc. See how she's acting, try to see if she's changed.
If you two don't meet up, you'll feel those doubts about "half of you wanting" shit forever.