Zelda Williams shares heartbreaking birthday post to the late Robin Williams

Robin Williams' daughter marked his birthday by donating to charity in his memory.

The Mrs. Doubtfire star - who took his own life in August 2014 - would have turned 65 on Thursday (21.07.16) and 26-year-old Zelda Williams admitted she was "not really sure" what to do, and found a good cause she thought her dad would appreciate her helping.

RELATED: Beautiful tribute made in honour of Robin Williams

RELATED: Never-before-seen Robin Williams outtakes from Aladdin

She wrote on Instagram alongside a throwback photo of herself, her siblings and her dad: "Still not really sure what to do on days like today... I know I can't give you a present anymore, but I guess that means I'll just have to keep giving them in your name instead."

She added: "This year, I tried to help three causes you cared about in one; rescue dogs, people suffering from disabilities, and our nation's wounded veterans, so I donated to freedomservicedogs.org.

"They rescue pups from shelters and train them so that they can be paired with someone in dire need of their help and companionship. Thought you'd get a kick out of furry, four legged friends helping change the world, one warrior in need at a time.

"Happy birthday Poppo. Shasha, Zakky, Codeman and I all love you and miss you like crazy. Xo, (sic)"

Meanwhile, Matt Damon recently admitted he will always treasure working with the late actor on his breakthrough movie Good Will Hunting, and credits Robin for changing his life.

He said: "Working with Robin almost defies description. He was one of the most generous, loving, wonderful people I've ever met. He had this capacity that I've never seen on a movie set.

"When everyone started to get tired and started to flag a little bit, he would launch into stand-up. We knew it was original because he was making fun of crew members and pulling them into these bits. It was like 15 minutes of the best stand-up ever that was just privately for us.

"Everyone would laugh and laugh and laugh and then everybody would get this boost of energy and go back to work.

"I'll never be able to thank him enough for what he gave us. In my heart, that's where he is, as this person that I'm deeply deeply grateful came into my life and changed it for the better."

Want more celebrity, entertainment and lifestyle news? Follow Be on Facebook,Twitter, Pinterest and Instagram.