The "Frozen 2" star previously revealed they had great success transitioning their eldest child, Lincoln, when she was still a toddler, so they never expected to face such a struggle the second time around.
However, she told fans on her Momsplaining with Kristen Bell digital series, "Currently, my youngest is five and a half, still in diapers," adding, "every kid is so different."
After admitting to being "mom-shamed" by fans who expressed their shock following the confession, Kristen told website Today's Parent that the pair has finally managed to get Delta to start using the toilet.
"The Good Place" star explained, "You know what we have to do? We wake her up at about 11 pm when she's, like, a zombie and put her on the toilet."
Dax added, "Yeah, we put a wet spaghetti noodle on the toilet once a night."
Opening up on the fan response to her revelation, Kristen reflected, "I think it's really normal and no one should feel ashamed if their kid has an irregular pattern for potty training."
"If you want to try this 11 o'clock make-them-pee trick, great, there's no shame in any of it. Sometimes it takes kids until they're even older than five," she added. "But I've never met a high-schooler who pees their pants all day. It's going to stop at some point."