With an estimated net worth of $4.2 billion, Milane Frantz is one of Forbes' richest billionaires as of January 2016, according to Forbes. She and her siblings, Danine Avara and Randa Williams, received $4.1 billion each as inheritance from their father, Dan Duncan. Each of their fortune increased by $1 million last year when the company's share elevated by almost 24%. Their father was once recognized as the richest person in Houston and third richest person in Texas.

Dan Duncan is the founder of Enterprise Products Company. The company started with two trucks which are used for door to door selling. Today, Enterprise Products Company is one of the most successful pipeline company with over 50,000 miles of gas, natural oil and petrochemical pipelines.