TLC's Sister Wives may be welcoming a new addition soon, as Robyn, also known as wife number four, is confirmed to be pregnant. While official news is yet to be released about the addition of a new member of the Brown family, Kody may have given it away via Twitter already. The news doesn't sit well with first wife Meri, who had been having problems with the polygamist marriage.

Tension is expected in the Brown household as the youngest of the sister wives, whom the legal wife Meri herself introduced to Kody, is adding another heir. The tweet was released during the July 20^th episode with the message being "Super Sol! Thanks @LuvgvsUwngs A cute little boy! Only the 3^rd shy child of 17...Should we have another? #SisterWives." Enstarz says that the addition of an 18^th member of the family will be an important issue that could be addressed in season 6, especially since Kody's first and only legal wife, Meri, is infertile.

It is already a concern among the wives that they have to fight for their shared husband's time and attention, particularly the legal wife, Meri, who had had hard feelings brought to the surface upon the Spring Break road trip to meet the Richards, another polygamist bunch.

Meri found herself in the same shoes as the Richards' first wife, Rebecca, who had "unresolved feelings" about her husband having a second wife. Enstarz also recalls Meri remembering days when Kody showed her love and affection, while she sometimes questions her importance to the growing Brown family and if her husband still cares for her. The Hollywood Gossip also recalls Meri having some "beef" with Janelle, which can be expected in their setup. Enstarz says that Meri even went as far as saying sometimes she "feels a sense of betrayal to the original marriage she had with Kody." She also said that she had lost opportunities for her personal growth because of the polygamist marriage.

As a temporary solution to Meri's infertility problems, Enstarz recalls Robyn offering to be a surrogate back in season 3.

It's not all brawl on the Brown household, however. Meri has been cited to joke about working on her relationship with Christine, whom she would want to go on a cruise even without their husband, The Hollywood Gossip reports. According to the site, "This is what adds to the appeal of Sister Wives. They are sticking this relationship out, even if there are moments they're not crazy about it."

The cast will be reunited in July 27 and the news about Robyn's pregnancy could be confirmed then.