Amber Heard remembered her mother Paige on what would have been her 64th birthday in a social media post she shared on Friday.

The "Rum Diary" star took to Instagram to greet her mother a day after her birthday. In the post, she reveals her heartache and how much she still misses her mum.

"Yesterday was my mom's birthday. They say the first one is the hardest," Amber wrote.

"I hope that's true...although nothing will ever lessen how much I miss her or will miss being able to tell her happy birthday. Here's to all the mamas out there," she added.

The "Aquaman" star included a photo that shows her and another woman leaning on each other as they looked at a small memorial of her mum Paige. She shared a similar picture on her Instagram Story. But this time, she has her arm wrapped around the woman, who could be her younger sister Whitney or according to Daily Mail, could be her girlfriend, cinematographer Bianca Butti.

"It's true it gets easier but never easy...all the love for you today," a fan commented on Heard's post and another wrote, "Love you both so much."

Amber shared the news about her mother's passing in May. She did not reveal details about the cause of death but expressed her heartbreak and devastation over her loss.

"I am heartbroken and devastated beyond belief at the loss of my mom, Paige Heard. She left us too early, clasping onto the memory of her beautiful, gentle soul. She will be missed from the very depths of our hearts forever, "she captioned a series of photos including a throwback of her mum cradling her as a baby.

"Her unflinching, open heart made her the most beautiful woman I had ever known. It's hard to imagine and even more difficult to say but I feel truly lucky to have been her daughter and been given the gift of having the light she shone on everyone, fall on me for nearly 34 years," the actress concluded.

Paige raised Amber and her sister in Austin, Texas where the actress has recently been spending time with her father David. She has been spending most of the quarantine with the horses as seen in her social media posts.

Amber Heard
Actress Amber Heard attends the 2016 Glamour Women Of The Year Awards in Hollywood, California Getty