Can my chinese wife convert my daughter nationality to Chinese without my consent?

I am a Malaysian and my wife is a Chinese. Our daughter is born in China but we registered her as a Malaysian citizen at the Malaysian Embassy. When my daughter was born, the hospital issued her a birth certificate as we need the certificate to register at the embassy. After we registered her at the embassy, she was issued a Malaysian birth certificate. Presently my daughter holds a Malaysian international passport and also identification card. Now we are facing some marital problems. My wife plans to go back to China for the coming new year and my daughter visa permits her stay for a maximum of 6 months. I am worried that she may not bring my daughter back to Malaysia.

Q1. Can my wife convert or apply for the Chinese citizenship for my daughter without my consent? I was told that since my daughter has a birth certificate issued by the local hospital there, my wife can easily change her citizenship as she can put my daughter name in her "hukou". Is this true?

Q2. Can she apply the citizenship base on jus sanguinis ("right of blood") since the mother is a Chinese citizen?