Ex wife still calls ex husband "daddy".

My mom still calls my dad "daddy", "honey", or "babe" whenever she's talking to him or about him to my siblings and I. They've been divorced for a year and while I understand that she misses him, it's disturbing. She cheated on him several times and had me as a result of one of her lovers. She abused my siblings, father, and I. She slept in the living room for the last 4 years of their marriage. My dad knew she didn't love him. But now that they're divorced, she can't let go. My dad has a girlfriend and is very committed to her but my mom still won't let go. How long could this take? I want to say something to her but we already have a horrible relationship. What can/should I do?