Engagement Ring (Material vs Commitment)

Regarding two questions related to the same issue. I bought and presented my Fiance with an engagement ring of her choosing. I asked for two conditions in return for my gift of commitment: 1. That she understand this ring means a serious commitment to me and should she change her mind prior to wedding me, the ring would be returned to me like a breech of contract. 2. I requested that in the event of her death one day that my biological daughter be the Heir of her ring as she has 3 children of her own to will the rest of her possessions and jewelry to. It would be have represented a sign of excepting my daughter by her into our blended family. Now that she has changed her plans for our marriage I requested back the ring and she complied. She resents having to give back what she claims is her rightful gift, despite our agreement from the start. I insisted from the first that this ring means a lot to me, it is not meant as a friendship ring but as a sign of a lifelong commitment. Am I wrong to withdraw my gift and also to have asked for her to pass the ring down to my child?

It is possible to give a conditional gift that returns to the giver of the gift if the condition was not met. Whether or not the condition you set upon your gift of the ring met the halachic requrements to make such a condition binding is irrelevant since your former fiancee complied with your request and returned the ring.