''Seeking Sister Wife:' ' Dannielle's Mom Says It's 'Hard' Seeing New Wife Join Her Daughter's Marriage

Seeking Sister Wife's season finale airs Monday at 9 p.m. ET on TLC

Dannielle Merrifield's mom still has some uneasy feelings about her daughter's unconventional marriage.

In PEOPLE's exclusive sneak peek at Monday's season finale of Seeking Sister Wife, Dannielle's mother questions if her daughter is making the right decision by bringing another woman into her marriage with her husband Garrick.

During a family trip to Mexico — which was arranged so that the family could get to know their Brazilian sister wife, Roberta — Dannielle's parents sit down for a candid conversation with their daughter.

Dannielle's father begins by asking her about Garrick's whereabouts, leading her to reply: "He's probably kissing his other wife."

Though Dannielle and her parents share a laugh over her remark, her mother admits that she was trying to avoid thinking about Roberta's involvement with her son-in-law.

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"I wasn't really trying to think about Roberta and Garrick being intimate in the house," she says in a confessional. "That's really their business. I don't really want to think about that."

Dannielle then asks her parents what they think about Roberta. "I know you don't like [how] the first meeting [went] and it was quick," she says, to which her father adds, "I think she's a sweet girl!"

Dannielle's mother chimes in, "I admire that you can have a relationship like that and not be jealous because I think I would be jealous."

"It's hard to see my son-in-law with another woman," she adds. "I hope Dannielle is making the right decision in all of this."

The family trip is also intended to be an occasion for Garrick and Roberta to conceive a child together. He already shares sons Geremiah, 11, and Solomon, 10 with Danielle.

But just as Dannielle's dad begins to ask his daughter about her feelings Garrick having a child with another woman, both Garrick and Roberta walk over.

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After sitting down with the group, Roberta makes a comment about the warm weather and proceeds to take off her dress and unveil her black bikini, saying: "Ooh la la." Following suit, Dannielle also removes her own swimsuit coverup to show off her pink bikini.

Garrick and Dannielle had been married for 12 years before Roberta entered the picture. The longtime couple found Roberta through an online search for another wife. Shortly after meeting the Brazil native in Mexico, Garrick proposed to Roberta. He is planning to legally divorce Dannielle to marry her, which would essentially forge a plural marriage.

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In a Seeking Sister Wife episode that aired in late May, Dannielle had a hard time adjusting to Garrick's desire to start his family with Roberta. Garrick and Roberta had originally intended to get married first, but they shifted gears as they experienced road blocks due to COVID-19 shutdowns.

"Knowing that Garrick and Roberta have changed gears, you know, 'We're not doing the wedding,' and they want to move forward with having a baby and starting their life together does make me a little apprehensive," Dannielle said in a confessional. "I do want to be supportive and I know the goal is for Garrick and Roberta to ultimately start a family together."

She added, "But with the pandemic going on and also communication with Roberta being very spotty [as she remains in Brazil], yeah — I don't know."

Seeking Sister Wife airs Mondays at 9 p.m. ET on TLC.