Billie Lourd speaks out after deaths of mom Carrie Fisher, grandmother Debbie Reynolds

"Scream Queens" star Billie Lourd is grateful for her fans and their support.

On Monday, the daughter of late actress Carrie Fisher took to Instagram to share a message with fans in her first statement since she lost her mother and grandmother, Debbie Reynolds, just last week.

>> Steve Martin's Carrie Fisher tribute tweet sparks backlash

“Receiving all of your prayers and kind words over the past week has given me strength during a time I thought strength could not exist,” she wrote. “There are no words to express how much I will miss my Abadaba and my one and only Momby. Your love and support means the world to me.”

>> PHOTOS: Carrie Fisher through the years

She shared a throwback photo of herself as a child with Reynolds and Fisher.

>> See the post here

On Dec. 27, Fisher died days after she suffered a heart attack on an airplane from London to Los Angeles. One day after her death, Fisher’s mother, Reynolds, died after suffering a stroke at son Todd Fisher’s home.

>> PHOTOS: Debbie Reynolds through the years

Todd Fisher appeared on “20/20” after losing his sister and mother and said the family plans to bury the mother and daughter together in a joint funeral.

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(h/t PEOPLE)