OUR EMPLOYEE MADE A SUB IN OUR STORE FOR A GIRL WHO SHE DOES NOT LIKE AND SHE LATER TEXTED THIS GIRL "ENJOY THE SPIT BITCH " wE HAVE PROOF OF THIS..CAN WE FIRE HER?

You can always fire an employee "without cause", as long as you provide her with the appropriate severance and there is no discriminatory reason for terminating employment. If, however, you are asking if you can fire her "with cause", the threshold for legally being able to do so is much higher. As an employer, you have an obligation to maintain a workplace free from harassment, which it sounds like this employee's actions would be classified as. However, you should consider a form of progressive discipline, such as a written warning and/or suspension, which clearly advises that future incidences will lead to her termination.