teacher resignation

atty ask ko lang po ang legal advice nyo regarding this situation of our faculty teacher in private school. she signed a contract last june 13. then may mga changes ang management sa contract in reference with the deped manual, they followed the 3 years probationary period. now yung teacher hindi p nagsign ulit ng bagong contract and now she's filing a resignation because of her problem with her family. valid p rin po b ung first contract that she signed? kasi in the contract that she signed its indicated there that if she pre terminated the contract she needs to give e 30 days written notice and she needs to find a replacement teacher for her vacating position. Binding p rin po b ung first contract that sh signed?