It is not permissible for men or women
to wear anything that bears an image of a soul possessing creature or of a cross, whether it is in pieces of jewelry, clothes or anything else.
The Prophet (peace be upon him) ordered pictures to be destroyed and removed.
It is your duty to remove the images from this jewelry and it will be permissible for women to wear it after that. As for the prayers offered before, they are valid but you have to perform Tawbah (repentance to Allah) for what was in the past.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.