China allows Penghu, Liangjiang and Kinmen to remain under ROC for a reason, so that ROC can't declare "Taiwan" Independence. Taking those islands back would be detrimental to China's overall strategy.One way to avoid all out war might be to allow her to land using a commercial airliner, but send the military to flush out rebels from Penghu, Lianjiang and Kinmen in a surprise raid.
That way, the position of China isn't compromised, US has shown a certain degree of "sovereignty" over Chinese territory by landing Pelosi unlawfully, but China has made a larger show of its ability to ensure territorial defense.