We spend $30,000 a year on au pairs to help with our 4 boys. It's worth it.

• Malia Smylie and her family have hosted four au pairs from Spain and Argentina.
• Each visit was so successful, and the mom of four said she regarded them as her daughters.
• She spoke about the pros and a few cons, she said, of the international program.

This interview is based on a conversation with Malia Smylie, 38, a nurse/midwife-turned marriage coach from Las Vegas. It has been edited for length and clarity.

My husband, Jason, 38, and I have four boys, ages 4, 9, 12, and 13.

They are rambunctious, but we like to call our household "controlled chaos." Still, after hosting four au pairs, we think our sons have learned kindness, openess and a taste of other cultures.

I would definitely recommend having an au pair. I'm always telling my friends that they'll never look back. We don't have one at the moment, but I feel joyful that we shared our home with some amazing girls who began life with us as strangers.

Our house is set up for an au pair

We started looking for our first au pair in 2017. I worked in nursing and midwifery, so my schedule was erratic.

Jason's job was also intense. He's the president of a sandwich chain, which takes up a lot of time. We needed a live-in, reliable carer who could step in often, rather than a nanny who might work 8 a.m. to 4 p.m.

Luckily, our house is perfectly set up for a fifth person. We have four bedrooms upstairs and a downstairs bedroom with a connected bathroom.

The floor plan optimized privacy for both the au pair and us. It meant that, if she were coming home late at night, there wouldn't be a commotion upstairs that would wake the kids.

You have to interview candidates online, and I was immediately drawn to Christina, 21, our first, from Spain. She wanted to chat with the kids to get an idea of their likes and dislikes.

She was like a big sister, patient and sweet, staying for 18 months. Then we hosted her fellow Spaniard, Judith, 18, who was loud, confident, and full of energy like the boys. They warmed to her immediately.

It helped that I spoke Spanish

Next, after two years with Judith, we hosted Esther, 21, also from Spain, who was a little more reserved than the others. Nevertheless, she was sweet and fun, and she stayed for a year.

Finally, there was Cami, 21, from Argentina. She was phenomenal during our year with us, too.

Some people are put off by the idea of having someone outside the family in their home. But these women became family. Of course, there was a getting-to-know-you phase, but they blended in while showing a different culture.

I'd say that it helped that I spoke Spanish. Still, Google Translate was useful at times.

With four guys in the house, I appreciated the feminine energy. Each au pair confided in me, whether they were homesick, having problems with a relationship, or had other issues.

The pros certainly outweighed cons. However, one of the major downsides was saying goodbye to our au pairs when they had to leave the US. It was hard on everyone, particularly the children.

The au pair program costs around $25,000 to $30,000 annually

You also worry about their safety when they go out at night, just as you would with your own kids.

Savings on having a full-time nanny were never a priority, but we figured out that, together with the agency fee, it probably cost us around $25,000 to $30,000 a year.

The weekly stipend was around $200, compared with $20 to $25 an hour for a nanny. But we didn't nickel-and-dime them.

Our au pairs could use the car whenever they wanted, and we always paid for gas. In contrast, some families will charge for that.

We're keen travelers, and our au pairs would usually accompany us to places like Europe. Several years on, they'll meet us on vacation whenever we're visiting different countries.

It's been an enriching experience for them and us. We're not biologically related, but we consider them daughters.