Complex sentence: And what's more, Dani isn't the only heir, she soon encounters a troublesome cousin she didn't even know she had, and even worse--her Great Aunt Marjorie has left her a large stack of debts and unpaid bills.
Split into simpler sentences: And what's more, Dani isn't the only heir. She soon encounters a troublesome cousin she didn't even know she had, and even worse--her Great Aunt Marjorie has left her a large stack of debts and unpaid bills.