The singer drops by Tuesday's episode of the Hulu series.
The singer and TV personality, who just announced she's expecting baby No. 2, guest stars in a new episode, which drops Tuesday on Hulu, as Ramona, the pregnant upstairs neighbor of Sophie's (Hilary Duff) in apartment 5C, who hires her to take photos of her home birth.
In ET's exclusive sneak peek from the latest installment, titled "Midwife Crisis," Ramona -- who's gone into early labor -- knocks on Sophie's door telling her that she's, well, gone into early labor.
"Why don't you grab your stuff and come on up?" Ramona asks Sophie, clearly uncomfortable as she holds her belly.
Turns out, Sophie may have signed up for more than she bargained for.
"The midwife's running late so you're OK setting up the birthing towel, right?" Ramona confirms to Sophie, who can only look back in shock. "Since you've shot a bunch of home births?"
As the contractions continue to get stronger, Ramona decides to leave, immediately regretting coming down in the first place. After she's gone, Valentina (Francia Raisa), who's been witness to the entire exchange, asks one very important question. Watch ET's exclusive clip above to see what happens next.
In the near future, Sophie is telling her son the story of how she met his father: a story that catapults us back to the present where Sophie and her close-knit group of friends are in the midst of figuring out who they are, what they want out of life, and how to fall in love in the age of dating apps and limitless options. Kim Cattrall plays older Sophie in the series and serves as narrator.
Recently, ET spoke with How I Met Your Mother's Jason Segel about whether he'd be open to appearing on the spinoff following Neil Patrick Harris' surprise season 2 cameo and Cobie Smulder's appearance in the freshman finale.
"Those people changed my life and I would do anything they ever asked me to," Segel said.
New episodes of How I Met Your Father drop Tuesdays on Hulu.