(ABC News) Speaking out for the first time since her mother, Carrie Fisher, and grandmother, Debbie Reynolds, died, "Scream Queens" actress Billie Lourd posted an Instagram photo of herself as a child with her mom and grandma, along with a message to fans.

“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,” Lourd, 24, wrote today. “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.”

Fisher, 60, died Dec. 27, four days after going into cardiac arrest while on an airplane. Reynolds, 84, died a day later after suffering a stroke, her family said.

Reynolds’ son, Todd Fisher, confirmed to ABC News that the family is planning a joint funeral for the two iconic actresses.

❤👩‍👩‍👧❤ 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. 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.

A photo posted by Billie Lourd (@praisethelourd) on