Going to Sierra Nevada with kids isn't a problem at all. The resort has a whole ecosystem designed for families, from snow gardens run by ski schools to sledding areas for those who don't even want to get near skis. Here are the real options, with schedules and prices, so you know what fits your child's age and what you're looking for.
Located in the Borreguiles beginner area, next to the area's moving carpet, Jardín Alpino is the resort's official snow garden, run by the company Cerogrados. Children learn using two moving carpets for exclusive use, in a facility that includes its own play room, rest area and dining room, designed so they can spend the whole day there without their parents needing to keep a constant eye on them.
The Borreguiles area has two green runs designed specifically for children who are already on skis (not just in the carpet area) to keep learning without losing the fun:
In Pradollano, next to the chairlift and at 2,100 metres altitude, Mirlo Blanco is the option for anyone who wants to spend a day in the snow as a family without going up to the slopes. Snow slides, ski-bikes, a tubing area with inflatable rings and the famous Russian sled.
Mirlo Blanco also organises children's birthday parties: a Russian sled ride, half an hour of the chosen activity and a snack at the Cabaña Fuente del Mirlo.
Unlike Mirlo Blanco, this area is in the upper part of the resort, in Borreguiles, and is reached by gondola from Pradollano, so you'll need an access ticket even if you're not going to ski.
Inside Snowpark Sulayr, one of the most complete in Spain, there's a specific circuit called Kidspark, with modules adapted so the youngest can take their first steps in snowboarding without facing the adult-level modules directly. It's located in the Loma de Dilar chairlift area.
A little further up from the resort, past the High Performance Centre and the Youth Hostel, Hoya de la Mora is the traditional free-access area. Natural hills where families slide on rented sleds or simply build snowmen, with no closed circuit or attraction schedule. There's sled rental and drink kiosks, and the Albergue Universitario offers a warm spot to have a hot chocolate. In peak season, the car park fills up quickly and access for new vehicles may be closed, so it's worth arriving with time to spare.
For the youngest members of the family, the resort has a nursery for children from 4 months to 6 years old next to the Al Andalus gondola (level -1 of the car park), where they can play, do workshops or rest while their parents ski.
Many of the schools operating in Sierra Nevada combine their lessons with access to one of these parks, so children get both technical learning and pure fun on the same day. If you're booking lessons for your children, it's worth asking the school directly whether they offer any of these combined packages.
On SnowTeach you can compare Sierra Nevada schools with programs for kids and book directly.