Dannine Avara

Dannine Avara and her three siblings inherited Enterprise Products Partners, the energy pipeline giant founded by their late father, Dan Duncan.

Formerly the richest person in Houston, Duncan died in 2010 at age 77 of a brain hemorrhage.

Duncan started Enterprise Products in 1968 with $10,000 and a truck; now it owns nearly 50,000 miles of natural gas, oil and petrochemical pipelines.

Avara's sister Randa Duncan Williams is the only sibling on the board of the company.