On Thursday, Wild actress shared a tribute to her mom on Instagram in honor of the special day.
"Happy Birthday to the most amazing Mama in the whole world!" Witherspoon, 46, wrote alongside photos of the mother-daughter duo smiling together. "Every day I get to hear you laugh while you tell the best stories is such a gift!"
She added, "Please keep bringing the sunshine into our lives 🌞💐💞"
Witherspoon's pals also sent their birthday wishes to Betty in the comment section. "Happy Birthday Betty!!!!!!!! Sending you love!!!!" Witherspoon's Little Fires Everywhere costar Kerry Washington wrote, while Sprinkles founder Candace Nelson shared, "Happy birthday Betty!!!!! 🥳🥳🥳"
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Earlier this year, the Oscar winner shared a funny video in honor of Mother's Day. "Happy Mother's Day to all the unconditionally supportive Moms out there! Thinking of those who are missing theirs today," Witherspoon captioned the post.
In the clip, Witherspoon quizzed her mom about her acting career, including her Apple TV+ series The Morning Show, which is currently filming its third season. When Reese asked her mom to name her favorite roles from her career, Betty hesitated for a second as the sound of crickets chirping played and the Big Little Lies actress made an offended face at the camera.
The Sweet Home Alabama star then asked if she should do more comedies, to which her mom responded: "I think you're great at comedy also." When asked where she got her sense of humor from, Betty answered, "Your uncle."
"Really? I thought I got it from you," Reese said, assuring her mom that she's very funny. "Yeah, it's probably me. It might be me," Betty responded.
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While appearing on The Drew Barrymore Show in 2021, Witherspoon was brought to tears speaking about the love and respect she has for her mother.
"I was talking to my mom on the phone when your producer called and said the whole audience was filled with nurses, and my mom and I both started to cry. Because being raised by a nurse, I think my mother has such infinite compassion."
"My mother worked night shifts, she worked weekends, so I had to kinda take care of myself; my brother and I would make dinner and everything. She was so tired, but she just loved her patients," she continued. "She did labor and delivery, she did neonatal intensive care. I would bring her donuts, her and the other nurses."
Witherspoon said she has always been "in awe of" her mom's "endless compassion for other people."
"And that's how I feel whenever I see a nurse because I think to dedicate your life to caring for people is one of the most noble professions that exists. Thank you for your incredible hard work, taking care of people during this very difficult time," she said.