The 30-year-old TV star - who got engaged to the singer-turned-presenter in November after four years of dating - would love to have a large family with her 37-year-old spouse but knows she might change her mind at some stage.
She said: "I turned 30 and I got engaged and I started really thinking about the next chapter. One of those is family.
"Ideally, I would love to have three or four, but ask me after the first one. Ultimately, I just want them to be healthy."
Vanessa and Nick have still not set a date for their wedding because they are so busy with their respective work commitments, but the 'True Beauty' host says they are now considering a winter wedding.
Explaining their delay in setting a date, she told People: "It's just because of our work schedules. For us, work is important. It's our creative outlet, it's what keeps us going, it keeps us busy, and we want to be sure that we work around that.
"I saw a wedding booklet about the Ritz-Carlton weddings that they do and it was a winter theme and it was beautiful.
"Something about winter, it's one of my favourite seasons, it's very romantic. The twinkle lights and the greenery and the snow. So that taught me I need to be more open-minded. We'll figure it out."