Sister Wives
Kody Brown's second wife Janelle.Facebook/Sister Wives

Kody Brown and his fourth wife Robyn will be preparing to welcome their next child when "Sister Wives" returns on TLC with season 6. While Meri and Christine have congratulated the couple, Janelle has been tight-lipped about it.

The second wife of the polygamist family was always against its restructuring. When the family patriarch and his first wife informed the rest of the family members about their decision to get legally separated for Robyn's children, Janelle had objected it.

"[I have] never been so great with change. I don't know what I'm in for. I'm worried it would change the dynamic. I know it's irrational... I'm worried somehow this would have you favour Robyn," she said.

Although Kody managed to convince his second wife and get her approval from divorce, it remains to be seen whether she will be happy to welcome 18th child of the family, who is likely to join them on 7 January.

Immediately after the family patriarch informed his fans about Robyn's pregnancy through People Magazine, Meri and Christine congratulated both of them on Twitter.

While Meri posted: "Congratulations @LuvgvsUwngs and @realkodybrown on your pregnancy. Happy for you both!"; Christine tweeted: "I'm so excited @LuvgvsUwngs is pregnant. I've been teasing her for months about having a baby girl for Truely to play with" and "Having a tea party with Truely. This serving is for @LuvgvsUwngs' baby. Might get cold...."

In the meantime, Janelle shared the news article about Robyn's pregnancy and re-tweeted Christine's post. But she did not leave any message for her husband and his fourth wife on the social media page. So it is not clear whether she is still worried about the changes that are going to take place due to the family re-structuring or preparing herself to welcome the new member.