If you grew up in the ’90s, it’s safe to say Mary-Kate and Ashley Olsen were part of your childhood. The twins earned their breakout role in the hit TV series Full House and quickly became household names with their careers as child stars, but it’s been quite some time since they took on any acting roles. Keep reading below to find out what the Olsen twins are up to in 2017!

Are Mary-Kate and Ashley identical or fraternal?

This is a popular question that fans are constantly asking, and the answer is actually surprising. Despite the fact that it was nearly impossible to tell Mary-Kate and Ashley apart when they were younger, they are actually not identical twins. They are technically sororal twins — which is the female version of fraternal — and there is a very specific difference between the two.

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(Photo Credit: Getty Images)

Scientifically speaking, identical twins occur when one fertilized egg splits off and produces two or more fetuses that share the same placenta and genes, which is why identical twins look alike and are usually the same sex. Fraternal or sororal twins occur when two separate eggs are fertilized by two different sperm, but the fetuses have their own placenta and share about 50 percent of the same genes, so they don’t necessarily look exactly alike. As Mary-Kate and Ashley aged (they are both now 31 years old), they started to look less alike.

There is another famous Olsen sister.

Mary-Kate and Ashley have an older brother named Trent, a young sister named Elizabeth, and a half-sister named Courtney and a half-brother named Jake. Elizabeth, 28, is slowly making a name for herself with her acting career, and her most recent role is in the 2017 films Ingrid Goes West, Wind River, and Kodachrome.

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Mary-Kate and Ashley with Elizabeth. (Photo Credit: Getty Images)

Mary-Kate and Ashley Olsen made a name for themselves with their movies.

The twins starred in a handful of straight-to-video and TV films that were produced by their own production company, Dualstar — with titles like 1993’s Double, Double, Toil, and Trouble and 1994’s How the West Was Fun, to 2004’s New York Minute. They made their feature film debut in 1995’s It Takes Two, starring alongside Kirstie Alley.

Mary-Kate and Ashley have a pretty impressive net worth.

They weren’t just film and TV stars. They also marketed themselves as a brand in the ’90s and sold products like books, toys, computer games, and children’s clothing. As they got older, they started to expand their fashion line and now, as of 2017, their combined net worth is $400 million.

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(Photo Credit: Getty Images)

Mary-Kate and Ashley are focused on their clothing lines.

The twins started their first couture fashion label called The Row in 2006 and they launched the contemporary line Elizabeth & James the following year. When Netflix announced that it would be rebooted Full House with Fuller House, fans were upset because Mary-Kate and Ashley didn’t reprise their role as Michelle Tanner. Their absence was addressed in the series premiere, when Bob Saget’s character Danny Tanner said, “Well, Michelle sends her love,” he says, “But she’s busy in New York, running her fashion empire.”

Mary-Kate is married, but Ashley is single.

Mary-Kate married French banker Olivier Sarkozy in 2015, while Ashley split from her financier boyfriend Richard Sachs back in March.