DON constantly texting me

You are not wrong.

Make an appointment to met with her. Say something about you like your job and working there. But your days off are very important to you. You need time to relax, forget about work, be with your family, etc. That receiving texts on your days off make the days off seem like you are still at work and interrupt your family time.

Also tell her when she texts you while you are at work you get distracted. Laugh and apologize that you are awful at multi-tasking. The interruptions cause you to lose track of what you were doing, or what you planned to do next.

Let her know she can always text you for serious important issues.

The world has become strange with fingertip access to anyone. So many think everyone is always available, and so many think they are always available. The phone rings and they have to answer. But there are few people in our line of work that would need to talk about work stuff outside of work.

Your first reply gave you the "adult" way to handle the problem. I offer a juvinile alternative passive agressive "ignore" option:

DON "did you get my text?"

You, "no, was it important?"

DON, "Not really."

Process continues until DON stops texting and only talks to you at work. Also works for work phone calls, or really for not talking to anyone you'd rather not.

Are you required to have your phone with you during work? Do you receive texts that are necessary to your job? If the answers are no, leave you cell phone in your locker.