They grow up so fast!
From the Kardashians and Jenners to the Olsen twins, there are plenty of famous siblings who’ve grown up right before our eyes!
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Click through the gallery to see then-and-now photos of celebrity sisters and brothers that will make you feel old.

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Demi Lovato Madison De La Garza
Getty Images, Instagram Demi Lovato and Madison De La Garza
Demi's little sister is now 16 years old, while the singer is 25.
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Justin Bieber Jaxon Bieber
Getty Images Justin and Jaxon Bieber
Justin's little brother is now eight years old, while the singer is 23.
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Paris And Nicky Hilton
Getty Images Nicky and Paris Hilton
Paris is now 36 and her little sis is 34.
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Olsen Sisters
Getty Images Mary-Kate, Ashley, and Elizabeth Olsen
Mary-Kate and Ashley are 31 years old, and their baby sis is 28.
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James Franco Dave Franco
Getty Images James and Dave Franco
James is 39, and his little bro is 32.
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Elle Fanning Dakota Fanning
Getty Images Dakota and Elle Fanning
Dakota is 23, while her little sister is now 19 years old.
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Britney Spears Jamie Lynn Spears
Getty Images, Instagram Britney and Jamie Lynn Spears
Britney's younger sister is 26 years old, while the pop star is 36.
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Jaden And Willow Smith
Getty Images Jaden and Willow Smith
Jaden is 19, while his sister is 17.
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Kendall And Kylie Jenner
Getty Images Kendall and Kylie Jenner
Kendall is 22 and her sister is 20.
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Ashlee Simpson Jessica Simpson
Getty Images Jessica and Ashlee Simpson
Jessica's little sister is 33 years old, while the singer is 37.
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Chris Hemsworth Liam Hemsworth
Getty Images Chris and Liam Hemsworth
Chris is 34 and his younger brother is 27.
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Beyonce And Solange Knowles
Getty Images Beyoncé and Solange Knowles
Bey's younger sister is 31 years old, while the pop star is 36.
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Hilary And Haylie Duff
Getty Images Haylie and Hilary Duff
Hilary's big sis is 32, while the actress is 30.
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Julianne Hough Derek Hough
Getty Images Derek and Julianne Hough
Derek is 32 and his sister is 29.
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Kardashian Sisters
Getty Images Kourtney, Kim, and Khloé Kardashian
Kourtney, Kim, and Khloé are 38, 37, and 33 respectively.
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Vanessa Hudgens Stella Hudgens
Getty Images Vanessa and Stella Hudgens
Vanessa's little sis is 22 years old, while the High School Musical actress is 29.
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Luke And Owen Wilson
Getty Images Owen and Luke Wilson
Owen is 49 and his brother is 46.
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Tia And Tamera Mowry
Getty Images Tia and Tamera Mowry
The twins are 39 years old.
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Maggie And Jake Gyllenhaal
Getty Images Maggie and Jake Gyllenhaal
Jake is 37 while his big sis is 40.
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Miley Cyrus Noah Cyrus
Getty Images, Instagram Miley and Noah Cyrus
Miley is 25 and her little sis is 17.
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Ali Lindsay Lohan
Getty Images Lindsay and Ali Lohan
Lindsay is 31, and baby sis Ali is 24.
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Jonas Brothers
Getty Images, Instagram Kevin, Joe and Nick Jonas
Now a father of two, Kevin is 30. Joe is 28, and Nick is 25. FYI, the "bonus Jonas," baby brother Frankie, is 17!
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Jack Kelly Osbourne
Getty Images Kelly and Jack Osbourne.
Kelly is 33, and her brother is now 32 — and a dad to two daughters.
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Nicole Sofia Richie Now Then
Getty Images Nicole and Sofia Richie
Big sis Nicole is 36, while her younger sister Sofia is 19.
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Taylor Austin Swift
Getty Images Taylor and Austin Swift
Taylor's 28, and her younger brother, Austin, is 25.