肚肚 is a little bit lower than belly

Sophia doesn't express herself very clear with language now. Thinking she's almost 22 months old, it's a bit slow. However I find she has ability to swich between English and Chinese.
She knows most of her body parts, some of them she understand, some of them she can say it in Chinese (as I know of). The first one she knew was nose, in Chinese, 鼻鼻.
Today, her teacher showed me that she knows where her belly is. I imediately asked her that in Chinese: 肚肚在哪里? She pointed somewhere lower than where she pointed her belly. I repeated a couple times, she did the same. It looks like she allocate her 肚肚 a little bit lower than her belly.
To test more, I asked her all other body parts in Chinese and English, she pointed them all right no matter what language I spoke.
Amazing!