6-year-old meowing

My daughter has been pretending to be a cat occasionally for as long as I can remember. She meows, crawls on all 4s, nuzzles up to you, and cries or whines like she thinks a tiger would. I have always tried to get her to outgrow this by encouraging her to use her words. Lately, I have become increasingly annoyed when she acts this way. I cannot stand it anymore and I'm about to snap. Tonight she started crawling on me (I'm two weeks away from my due date), grabbing my boob (not okay!), and nuzzling my neck. It's making me extremely uncomfortable. I raised my voice and grabbed her hand, moved it away from me, and told her to STOP! "I will not talk to you until you are a little girl again. I cannot have a conversation with a CAT!" How can I get her to stop? It's driving me insane and she is getting far too old for this.