Children have a natural sensitivity to crystal energies. Let them choose using their intuition.

Cleansing:
Find a houseplant:

Place your crystal in a healthy houseplant. Salt
Lay your crystal in a bed of natural sea salt (not iodized). Bury the crystal or lay it on top of the salt for several hours or overnight. After the salt has absorbed all of the previous or negative energies, discard the salt outside and rinse your crystal with cool water.

Water
If you live close to natural water from streams, rivers, or the ocean, take advantage of the flowing water for the cleansing of your crystal. Filtered water will also work. Find a glass bowl to place your crystal in and submerge them in water for a few hours. Once you feel the crystal has been cleansed, discard the water outside. Don’t overthink it! Use your intuition with cleansing. You can ask your crystal to let go of any previous intentions before setting your own. Remember, you are building a relationship with your new crystal friend.

Charging
The Moon New and Full Moons are great to work with. Leave the crystal outside to bathe in the moonlight or on a windowsill to grant them the potent effects of the new and full moon.

The Sun
The sun holds powerful energy. Place your crystal outside in the sunlight or on a windowsill for a few hours to get a strong charge.

Hold the crystal and speak your intention out loud. Visualize the crystal accepting it. Intention is EVERYTHING.

Spend time with the crystal until you feel it holds your intention. Place your charged crystal where needed. To work with children, consider using The Intention Teddy to keep the crystal safe and prevent misplacement. Store the crystal in a double-knotted pouch to be kept with you, under the mattress, next to a bed or inside The Intention Teddy.

Maintain the relationship with the crystal. Talk to the crystal, ask them to share their energy with you, and call on them when you need them.