"Anytime that you expand your family, there's going to be a shift," Meri explained to a news outlet ahead of the Season 18 premiere of Sister Wives. "You've got just the logistical things, but then you've also got the emotional things."
"I'm human. I'm going to get jealous," she added. "He's human. He is going to not know how to deal with a woman's jealousy."
The mom-of-one — who shares Leon, 28, with Kody — also pointed out that they are taught through their church that feelings of jealousy should be dealt with privately and hidden away. This is a lesson she's since realized isn't good advice for her.
"I remember Kody would ask me, 'If you're okay with them coming in the family, why are you jealous? Why are you having a hard time?'" she continued. "Well, one, I'm human. Two, I didn't understand that it's okay to be jealous. I thought I was a bad person for having those emotions."
"Now, I understand that jealousy is okay," she noted. "It actually can be used as a guide. And before, it was like, oh, it's wrong. I'm a bad person."
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Aside from the teachings of their church and the natural, personal struggles that can come with polygamy, Meri also confessed that she was not mature enough to handle plural marriage at such a young age. The TLC star was only 19 years old when she said "I Do," while the father-of-18 was 21 years old at the time.
"When you're 20, 21, 25, 30, whatever, when this is happening, you're not grown up enough," she claimed. "Or maybe it's more not that you're grown up enough, but more that you just don't have the tools in your tool belt to know how to deal with some of these issues."
As OK! previously reported, Meri and Kody confirmed they'd made the decision to end their marriage this past January, following years of relationships struggles.
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Watch the premiere of Sister Wives Season 18 on TLC on Sunday, August 20.
Meri spoke with People about her battles with jealousy.