'Teletubbies' Sun Baby Is Pregnant, Expecting Own Baby at 27

Jess Smith -- AKA the Sun Baby from the popular children's show, "Teletubbies" -- is expecting a little ray of sunshine of her own ... do ya feel old yet?

The former child star, who's now 27 years old, announced she's pregnant with her partner, Ricky ... posting shots of her ultrasound, and giving fans a first look at her child-to-be.

Fans of the series remember Jess playing the character for years ... overlooking Teletubbyland -- where Tinky Winky, Dipsy, Laa-Laa and Po all lived.

Jess appeared when the show debuted in 1997, starring when she was just 9 months old -- she stayed on the show until 2001 when she was no longer a baby in real life, obviously.

She claims she was cast on the show while being weighed at the hospital -- saying producers for the children's series were in the hospital looking for smiley, laughing babies to use for their new show, and Jess fit the bill perfectly.

BTW, there have been several spin-offs of the kids' show over the years ... but if producers are looking to make a proper reboot, we know just the baby for the job.