In an interview with Gala Magazine, the actress admitted that she and husband Josh Kelly have discussed giving their 9-month-old daughter Naleigh a sibling in the near future.
"We would like to have a second child - adopted or biological," she explained.
"We're not ruling it out."
Heigl said that the recent earthquake in Haiti inspired her to expand her family after seeing how many children lost their parents in the tragedy.
"Just look at Haiti. There are so many parentless children. It breaks my heart. I want to help."