Wearing shorts, a crop top, fake tan and heavy make-up, Kian commented that she may need some sort of "make-under" after she left the stage.
Speaking to the Herald, married Kelly (19) said she would be happy to tone it down for Kian -- but is looking to Beyonce when it comes to performing while pregnant.
She said: "I don't mind changing my style for Kian. My clothes will have to change anyway because I'm pregnant so I'll have to get maternity clothes -- that'll be new for me."
But the young singer said she won't change her look completely.
"I won't change my look completely and I won't change my personality. I am who I am and I don't think Kian wants me to change either. I'll just tone it down and pare it back a bit.
"Clothing isn't everything and you know what they say -- change is good. Just as long as it isn't too big a change."
The young star surprised listeners of Ryan Tubridy's radio show and mentor Kian yesterday when she announced live on air that she was 26 weeks pregnant.
She said she was in the early stages of her pregnancy when she auditioned for The Voice and had not reached the 12-week mark.
She said: "I'm due in April when the live finals are going on. Hopefully everything will go okay and I won't have to be go from the Helix to the hospital.
"Beyonce was still performing when she was pregnant," she said. "Women are healthy when they're pregnant -- they can still dance about. I'll still be dancing about on stage.
Mentor Kian (32) joked: "The pregnancy helps with the emotional side. I think it's great. Fair play to her."