Legal Question in Family Law in California

Technically yes, although between sick leave, disability, etc. available to supplement her missing income, the impact is most likely not going to be worth going to court over. The bigger issue is that the new child will entitle her to what is called a "hardship deduction" adjustment to the support calculation. That WILL increase your support permanently.

You should object to a hardship deduction as the father of the child has a duty to support the child. In cases such as this the allowance of the hardship deduction is discretionary with the court. You need to prepare to retain an attorney to assist you in this case.