Since you are an adult, you are free to do whatever you want with your name. What if you got married and changed your name? Would she object to that too? You are like in your 30s? Grown woman on your own? Why would she care? But then again I have strange parents too. They sometimes care about strangest things. Nothing surprises me. As my therapist says “don’t let them get to you and prevent you from enjoying your life.”