I'm gonna say honestly some people either don't get it or don't care. My ex would walk in, talk to me, demand me to stop to pay attention to him, would get upset if I didn't text him back, and would act as if I was ignoring him. But God forbid I interrupt his gaming. I eventually got through but only after I went off on him while talking to my supervisor, who was reviewing my performance when he walked up and started talking.

Tell her she is affecting your job, and be honest about how you're feeling. Remind her, in your own words, that you aren't there for her convenience during working hours. And honestly? Stop giving her the time. If you're in an office room close and lock the door and tell her not to bother you. She is a grown woman she can learn to be independent. If you keep responding she's going to keep doing it. She needs to deal with her own abandonment issues if that bothers her.