Creating a Power of Attorney: Power of Attorney to My Wife

My question involves estate proceedings in the state of: California and China

My wife and I live in California. I'm a US citizen while she is still a Chinese citizen with a green card. We have Real Estate in China we want to sell, which is under both our names.
She will making trips back to China without me to hopefully sell this property.

Question: How do I give her power of attorney in China so that she can sell the property without my presence ?

Creating a Power of Attorney: Power of Attorney to My Wife