What should be done to examine my lover?

I love very much a girl and she loves me back. We want to marry with each other but she says that she will not marry without permission of her mother. Her mother is against our marriage because we are inter-caste and old people still believe in inter-caste marriage restriction in my locality. yesterday she told me that she will marry where her mother will say her to marry. whether it may be me or not. And yesterday I really thought about suicide once. Now I am thinking about a plan by which I will make her mother agree for our marriage. But now I really wants to examine that she really loves me or not? Plz Help.