Lourd, 24, has been making a name for herself like her iconic family, being featured in last year's "Star Wars: The Force Awakens," set to appear in "Episode VIII" and also co-starring in the show "Scream Queens."
After the news that Reynolds, 84, died Wednesday night, Curtis wrote, "There are no words. Just that we all want 2 surround Billie with loving strength & support. Please give her space media. Please. Please."
"Right after I took this pic I realized how much Bill looked like Carrie. Both so beautiful. RIP Carrie, you were amazing... and thank you for making such an incredibly brave, kind and brilliant person who I'm lucky to call my best friend," she wrote.
She also wrote on Twitter Wednesday night after Reynolds died, "this world isn't fair.”
Finally, Taylor Lautner wrote an especially sweet message commending Lourd's strength.
"This girl is one of the strongest, most fearless individuals I've ever met. Absolutely beautiful inside and out. I'm lucky to know you @praisethelourd .. ??, me," he wrote of Lourd, Fisher’s only child.
Here are a few more: