California: Is a non-custodial parent obligated to pay for 18 year olds trade school?

Hi, I was just notified that my 17 year old child enrolled in a trade school. I was never informed or involved of the situation. Unfortunetly, we have a very distant relationship and do not communicate. I have adamantly paid my all of my child support and my child turns 18 next month (March). My child support ends in June. My childs mother is demanding me to pay for his school and is threating me with legal action, but I was never involved or informed of the situation until everything was past tense. I am in financial hardship and cannot pay, however; I did state that I would leave the Health insurace active. Has anyone gone through this or could you please post references. Thank you