Floor level is the foundation of safe handling
Most injuries to small pets happen in falls, so the single most protective rule is that children hold rabbits, guinea pigs, hamsters, and other small animals while sitting at floor level on a low cushion, never standing or walking around carrying them. Set the child down with legs together as a soft boundary, and settle the pet gently onto their lap with your own hands, positioning yourself close enough to support or retrieve the animal instantly. A guinea pig that wriggles free at lap height lands on carpet; the same wriggle from standing height can break bones.
Hands that a small pet can trust
Show the child how to stroke in the direction of the fur with a flat, slow hand, how to support a rabbit's hindquarters rather than lifting by ears or scruff, and how a hamster should be scooped from below with cupped hands once it is awake and walking onto them willingly. Squeezing around the middle, grabbing from above like a swooping predator, and chasing a pet around its enclosure all frighten small animals and are how bites happen. A child who waits for the pet to come to the hand learns the skill that makes every later handling easier.
Reading the pet and ending at the right moment
Teach the child the signs that the animal has had enough: a rabbit kicking, grinding its teeth, or scrambling to escape, a guinea pig freezing rigidly or crying out, a hamster trying to bite or dive from the hands. Sessions of a few quiet minutes that end while the pet is still calm build confidence on both sides, while pressing on teaches the pet that handling does not stop when it protests. Hand the pet back to its enclosure yourself, and let the child offer a treat or fresh hay there as the closing ritual instead.
Protecting the child as well as the pet
Supervision runs both ways: a startled rabbit can scratch hard, a frightened hamster can bite a finger it mistakes in a sudden grab, and any child who has been handling pets should wash hands thoroughly afterwards, especially before eating. Keep handling away from mealtimes, keep younger toddlers to stroking a pet that an adult is holding securely, and never leave a child and a small pet alone together even briefly, however gentle both usually are. Calm voices and no sudden snatching at the animal protect small fingers as reliably as they protect small ribs.
One set of rules for the whole family
Children get confused fastest when different adults allow different things — one grandparent permitting carrying, another insisting on floor only. Settle the household rules together: floor seating, adult places and retrieves the pet, sessions stay short, hands washed afterwards. Writing those rules down where supervising adults can find them keeps them consistent even when a babysitter or visiting relative is supervising, so the handling boundaries a child follows stay the same whoever is on duty. Profile access for this small pet can be handed to selected relatives using KinsLe Family Sharing.