Going bilingual

Hubby and I speak different languages to Yiu Yiu, hubby predominantly in Mandarin while I, predominantly English. She understands instructions and conversations in both languages and she recently can tell the same words in both languages.

While having dinner with my mum,
Yiu Yiu: Po po, mei mei (referring to Xiaoyu, her little cousin) leh?
Grandma: Mei mei sui jiao.
Yiu Yiu (turning to me): Mummy, mei mei sleeping ah.

Yiu Yiu (talking to Xiaoyu): Mei mei call Yiu Yiu che che.
Yiu Yiu (repeating herself in Mandarin): Mei Mei jiao Yiu Yiu che che.