Heather Rae El Moussais filled to the brim with love for her little family.

“Never in my wildest dreams did I think my heart would be so full from being a step mommy… and now I get to be a mommy, myself ❤️,” Heather wrote of her relationship with the children.

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Christina Cernik

Tarek and Heather El Moussa

The couple were in the middle of in vitro fertilization treatments and had even scheduled a date to transfer an embryo next fall when they got a happy surprise,they shared with PEOPLE exclusively.

“It was a huge shock,” Heather said. “We just weren’t expecting this. We had just gone through IVF. We had embryos on ice. We had a plan.” But after the disbelief wore off, theSelling Sunsetstar was elated. “I think when you least expect it and there’s no stress in your life, the world just brought us what was meant to be. I’m so excited that it happened like this.”

Heather Rae Young/Instagram

Tarek El Moussa and Heather Rae Young

Heather also revealed that when she and Tarek first got together, they weren’t planning on having kids, but her time as a stepmom changed that. “I really love being a bonus mom to Taylor and Brayden. They’re such incredible kids and I love them so much,” she said. “But as your love grows more and more and you fall deeper in love with someone and you build this life together, I started picturing myself having a child with Tarek. I started thinking I just wanted to create something with the man that I’m in love with.”

Tarek and Heather El Moussa

Heather also praised Tarek for being “such a good dad.”

“I’m just obsessed with my kids,” Tarek said. “They’re my everything, so having another one is just icing on the cake. I’m so excited.”

source: people.com