However, 22-year-old Ariel's dressed was HEAVILY criticised online for looking 'trash'' and being too revealing.
"What’s up with Ariel Winters outfit tho?" one person wrote.
"What was she thinking... seriously," another commenter chimed in.
Thankfully, Ariel's on-screen sister had her back.
"You know that she’s [fire emoji]?? I KNOW. That she's a sexy and confident woman," Sarah fired back.
A lot of fans were defending the Dunphy sisters.
"Good for you!! Please keep standing up for her because this is ridiculous," one fan replied to Hyland.
Sarah shared a bunch of photos from the party posing with various actors from the beloved show.
"I love these people with all my heart. 11 years together is proof you and your tv sister will start wearing the same outfit, siblings for life will be made, and you’ll forever fight over the same professor 😂 We’ll always be Dunphys and we’ll always have each other ❤️" Sarah captioned the gallery.