Ayame wasn't sure if Kagami was aware of it or not, but she was from a family that was very financially stable.
Frankly put, she was rich, and because her parents were rich and in the family business, her parents wanted to marry her off to another rich family's son to keep the wealth and investment together.
It was something that stressed her out but whenever she was with Kagami, all her fears and worries washed away. He didn't love her for her money; he loved her for who she was. Ayame hoped she would never take Kagami for granted.