Nikki Bella is open-minded about having more children

She shared: "I told Artem ... 'When I'm 39, if we feel so great in life and comfortable and you really want to try and have a little girl or just another one, and I feel that it's right as well, we can do that.

"I would like, if we did have a second, [to have it] right at 40 or right before 40."

Nikki is loving the challenge of motherhood, describing Matteo as her "best buddy".

She told Us Weekly: "I want this time with just my son ... I just don't want to have another baby interfere with that right now because I go over to [my sister Brie Bella's] household and I'm like, 'This is a lot. Boy, does two change it.'"

By contrast, Brie insists she won't have any more kids.

The 37-year-old TV star - who Birdie, four, and Buddy, 14 months, with her husband Daniel Bryan - is loving seeing her kids and Matteo growing up together.

Speaking about Matteo and Buddy, Brie recently said: "They're growing so fast, but they're growing exactly the same.

"We're always like, 'They're twins!' Both of them are walking. Both of them love to pick up stuff and throw [it]. They both climb the couch the same ... and jump. They're wild and fearless."

Brie - who has been married to Daniel since 2014 - also observed that her nephew is the "more sensitive" baby of the two.

She added: "Buddy is already a wrestler."