Chrissy Teigen and John Legend are making plans to give their nine-month-old daughter Luna a baby brother.

The model and TV presenter, who underwent In Vitro Fertilization (IVF) treatment to conceive her daughter, admits she and her husband have a son "on ice”.

She tells news show Extra the couple elected to have a girl first, and now she and John are seriously thinking about baby number two.

"(John) goes on tour, I think, all of May, so after that, I guess,” Chrissy says, adding her man is more than willing to add to the family.

"He’s literally like, ‘Please unfreeze me,'” she giggles.

Over the weekend (28-29Jan17), Chrissy responded to a social media user who asked why the couple used IVF, writing: "@chrissyteigen, did you give it a minute to try naturally or are you avoiding 'the act'?"

She addressed the rude question, tweeting: "Hi Linda, thanks for asking, you complete witch. I tried for about 9 years. Anything else, let me know!"

She also revealed that Luna is going through a phase, which is all about her dad - and she can understand.

“Like me, she’s all about daddy," she smiles, "but she has my attitude... I feel for John now!”

Chrissy is convinced Luna has also inherited her rather loud laugh: "When we laugh, we laugh really big, but it takes a lot for her to laugh out loud - you have to really go for it, you have to shimmy and shake, do all these wild things. It’s not easy, but I kind of appreciate it."