Dear Abby: My estranged sister is making me miserable

Dear Abby: My sister and I are estranged due to her history of drama and stirring up trouble. She has recently begun sending me nasty voicemails and texts. She had a bitter divorce several years ago and no longer has a relationship with her daughter or grandchildren. Because she’s miserable, she is now trying to make me miserable. I’ve been ignoring her and not engaging, but I’m tired of it. Should I confront her? (She’s not someone who’s reasonable.)