Demi Lovato's younger sister Madison De La Garza 'thankful' she can wish star a happy birthday

Madison De La Garza, 16, wished her half-sister, Demi Lovato, a happy birthday on Aug. 20 in an emotional Instagram post. (AP/Getty)

Madison De La Garza wished her half-sister, Demi Lovato, a happy birthday in an emotional post on Instagram Monday — nearly a month after the singer suffered an apparent overdose.

In the post, De La Garza reflected on a grim alternate reality that could have unfolded.

“Today could have been one of the worst days of my life, but instead i get to spend it thanking God, the incredible doctors, demi's team, and everyone across the world who offered their support - without all of these people i wouldn't have my big sister anymore,” she wrote on Lovato's 26th birthday.

The 16-year-old also described her famous sibling’s personal quirks.

“I've been thinking about how i wish that everyone could see the silly little things that she does, like how her nostrils move when she says certain words and when she brushes my hair behind my ear when i'm trying to sleep, because those are the things i'm thankful for today,” she continued.

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De La Garza added, “They seem so small, but those little things make up my sister - not a singer, not a celebrity, and definitely not what she's been described as in the media - she's a daughter, a friend, and my big sister... and i am so, so thankful that i can tell her happy birthday. #happybirthdaydemi ❤️””

The teen's post has received more than 100,000 likes and 5,100 comments as of Monday evening, with many wishing Lovato a happy birthday. Others praised De La Garza’s personal message.

“That's so beautiful!! God bless this wonderful family. We love you 💜💜” one fan wrote.

Demi Lovato and her sister Madison De La Garza in 2011. (Getty)

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“Such beautiful words, sisters are so important! ❤️ #happybirthdaydemi” another commented.

“I'm in tears this is beautiful😭 sending love to our angel❤,” one person admitted.