Social training for a child who isn't fully understanding what social situations are supposed to look like takes time.
I would start at home. Each night at the dinner table, go around and have everyone share 3 good things and 3 things they'd like to have improved about their day. Tell the entire table, "when people are talking, it's important to stop talking and listen to what they have to say without interrupting or monopolizing the conversation. We pay attention to their face and body. When they finish speaking or ask us a question, we know it's our turn to talk. Let's practice. I'm going to tell you about my day. I want you to listen, and then ask me questions about my day without talking about yourself. When I'm done telling you about my day, it will be your turn, and then Daddy's and then Sister's. When it's not your turn, you practice being a good listener."
Be sure you gently correct her each time she tries to interrupt, monopolize, or draw attention to herself (including a rude, bored look, sighing, or tapping, or laying on the table). Remind her about how we respect everyone in the family by giving them our attention. "Stop, DD. It's ___________'s turn now."
If necessary, you might have to tell her to go to her room for a bit of a time out. "I see that you can't stop talking about yourself and just listen, DD. This behavior is rude and unacceptable. Please go to your room and think about how a converation is supposed to be. When I call you, we'll try again."
This has worked wonderfully with my younger child who LOVES to be the center of attention.