Does anyone know why Tammi and Talia don't have the Menendez name?

Shouldn't they?? They've been in Erik's life for 30 years now! Why choose to keep a child r*pists surname? Also why write Menendez for your social media stuff like are they just using Erik?? 🤔 I feel like they are still ashamed of him. Tammi made that clear when she didn't want him to do the 2024 documentary on Netflix. She makes everything about her!