Under Israel's Law of Return, the right of return is granted to those born Jews (having a Jewish mother or maternal grandmother), those with Jewish ancestry (having a Jewish father or grandfather) and converts to Judaism (Orthodox, Reform, or Conservative denominations—not secular—though Reform and Conservative conversions must take place outside the state, similar to civil marriages).
Consequently, Gabrielle (Gavriella) has the right to return to Israel if she chose to. And if she so chose, I would welcome her as a sister.