Polish passport with less than 6 months left.

Hi,
I am planning to use the visa free transit in Beijing with my family the first week of January, flying from Singapore and then to Hong Kong.
My wife's passport (from Poland) will expire on June 30th 2020, so she has more than 3 months but less than 6 left on her passport.
Is it ok and can I organize this trip and start booking flights and hotels?
Thanks!