Don't give her signals that you are interested. Establish a common interest with her (E.g. movies) then use it to get her number (E.g You'll message her when you find a DVD you're both interested in). Then talk to her outside of work so the two of you develop an outside of workplace connection / relationship. Take it from there.
Good luck!
Don't cry, don't regret and don't blame
Weak find the whip, willing find freedom
Towards the sun, carry your name
In warm hands you are given
Ask the wind for the way
Uncertainty's gone, your path will unravel
Accept all as it is and do not blame
God or the Devil
~Born to Live - Mavrik~