If a person is in jail and they post bond can the bond be revoked and if so for what reasons?

I am witnessing a murder trial were a woman will be sentenced to life without parole for the death of a minor( a baby). She was released previously on bail for $50000. They put her back in jail because they said the situation changed but she always complied with what the court asked of her as far as her obligations to her bail requirements. Can the court put her back in jail and if she's acquitted, can they reinstate her bail and if so why? Of course Im on the woman's side.