Jessica Simpson revealed her daughter’s birthday wish was for grandfather Joe Simpson’s cancer treatments to work — and it came true.

The “With You” singer took to social media Saturday to thank her 11-year-old daughter, Maxwell, for her “powerful” act amid the Simpson family’s tumultuous time.

“She told me after she blew out HER 11 candles…’I made a wish that was for me and you and actually the whole family.’ I said Maxi it should be your wish and she said ‘we have the same wishes Mom,’” Jessica explained in the caption of her post, which featured a snap of her being lifted by her mini-me.

“3 days later on our way back to Cali she overheard me reading a text from my Dad and asked my mom sitting next to her ‘GiGi if my birthday wish came true already can I say it out loud or do I still keep it to myself?’” she went on.

“My mom told her to share it with everyone if she wanted to, especially if it had already come true….”

The “Dukes of Hazzard” star then revealed her daughter’s birthday wish “was for her Papa Joe’s bone cancer treatment to work,” proudly sharing that the recent treatments were in fact successful.

This marked the first time Jessica ever revealed her father, 65, was battling the disease.

“Thank you Maxi Drew for usin’ your wish on our family and most importantly, my Dad,” Jessica gushed.

“You are mesmerizing, steadfast, intelligent, passionate, generous, loving, devoted, inspiring, enticing, confident, empathetic, powerful, intuitive, beautiful, DETERMINED, enlightened and FULL OF WONDER. The faith of a child is what keeps all of us ALIVE.”

In the Instagram snap, Maxwell looked like the spitting image of her A-list mom, as she wore a black graphic sweater and beige trousers.

The “Open Book” author, 42, looked practically giddy as she straddled her little girl while rocking a bright yellow jacket, black leather pants and black-and-yellow socks.

Elsewhere in her caption, Jessica reflected on the impact Maxwell has had on her life. “I felt her purpose in my life when I was a kid and I would pray for my future daughter every single day and night,” she wrote.

“I know that most Moms would say please slow down time when their baby turns 11, but I have truly known her my entire life. Reading back on 30 yrs of conversations with God throughout my journal entries, it is evident that Maxwell was already living inside of my heart and my purpose.”

As previously reported, Jessica’s father was initially diagnosed with prostate cancer in September 2016, but was declared cancer-free in May 2017. He is also the father to Jessica’s 38-year-old sister, Ashlee Simpson.

In addition to Maxwell, Jessica and husband Eric Johnson are also parents to Ace, 9, and Birdie Mae, 4.