She's known for her role on one of TV's biggest sitcoms.

But Ariel Winter's career will take a dramatic turn on Thursday as she appears as a guest star on tonight's episode of Law & Order: Special Victims Unit.

The 21-year-old Modern Family star tweeted on Thursday: 'Tomorrow 10/3 at 10pm PDT I'm honored to be a guest star on my favorite show ever @nbcsvu there's a limit to how much I can write here so check out my Instagram post to see me about this incredible experience #LawAndOrderSVU'

On-screen: Ariel Winter's career will take a dramatic turn on Thursday as she appears as a guest star on tonight's episode of Law & Order: SVUWinter paired the tweet with several behind-the-scenes shots, including one of herself and Mariska Hargitay, who portrays NYPD Captain Olivia Benson on the show.

The actress took to Instagram to elaborate on her character Regan further, saying that she is a 'realistic person' who is 'still figuring herself out.

Winter's episode will grapple with being a 'credible victim,' but she added that 'making mistakes, or experimenting with things some may frown upon, does not mean you should be an open target for sexual assault. NOTHING anyone does could EVER possibly warrant that.'

Picture perfect: Winter paired the tweet with several behind-the-scenes shots, including one of herself and Mariska Hargitay, who portrays NYPD Captain Olivia Benson on the showShe also posted more photos of herself to Instagram with Hargitay, captioning one of them: 'Mariska worked with me not only as an actress but as a person, and I feel I have grown immensely from the experience.

'The amount of care and interest she showed in me as a person was amazing.'

Winter added: 'She was truly interested in my life story and always made me feel heard.

Action! The actress took to Instagram to elaborate on her character Regan further, saying that she is a 'realistic person' who is 'still figuring herself out

'She was honest and gave me some of the most accurate advice I've ever been given.'

Winter continued to lift Hargitay up with her closing comments: 'People like her are RARE in and out of this industry.

Her episode will air Thursday at 10 p.m. on NBC.

Director's chair: Winter's episode will grapple with being a 'credible victim,' but she added that 'making mistakes, or experimenting with things some may frown upon, does not mean you should be an open target for sexual assault. NOTHING anyone does could EVER possibly warrant that'