To say "baby" in Chinese, you can say "宝宝" (bǎo bao).
姐姐 [jiě jie]
It depends on what dialect you are speaking. Mei Mei is little sister in Mandarin Chinese.
In Chinese, you can say "我爱你,小妹妹" to express love to your little sister.
Just say it.
There are many styles of Chinese. See related link.dì mèi
In Mandarin Chinese, you would say "妹妹" (mèi mei) for little sister.
Chinese is a bit more specific when it comes to people in our family. There are two ways to say sister in Chinese. Jie Jie (姊姊) means older sister while, if it is your younger sister it is mei mei (妹妹).
petite soeur
Niece = female Nephew = male
You can say: Woo Xiang Gan Ni.
i will say the babys aunt