Make room for a step stool in a small bathroom
Choose a stable place for a purpose-made step stool that supports supervised use without blocking a small bathroom.

Check the stool and the floor together
A stool that fits beneath the sink may still be awkward when someone stands on it. Use a product intended for stepping, within its stated load and age guidance, and inspect its feet, treads and structure. Do not substitute a storage box, decorative stool or stacked object. Set the whole base on a level surface rather than partly on a bathmat.
The bathroom floor can become wet, so the stool's position needs regular attention. Dry spills and keep the feet and standing surface in the condition the manufacturer requires. A nonslip label is not a guarantee against every fall, and young children still need appropriate supervision.
Test the reach without encouraging climbing
Position the stool so the intended user can reach the sink as designed without stretching sideways or leaning against unstable fittings. Check whether the faucet is reachable and whether opening a drawer would strike the stool. A taller stool is not automatically the solution if it puts the user too close to hazards or makes stepping down difficult.
Do not alter the stool's height, add homemade steps or paint over its grip surfaces. If the fit is wrong, choose a suitable product or change the routine. Keep medicines, razors, cleaning products and electrical appliances securely stored; adding a step changes what a child may be able to reach.
Give it a parking position
In a small bathroom, the stool should have a place when it is not in use. It may slide into a clear area beside the vanity, provided that does not trap moisture or obstruct a door. Avoid balancing it vertically where it can fall or leaving it in the path between the toilet and door.
If the product folds, follow its locking and storage instructions and consider pinch points and who will operate it. A compact folding design is not necessarily the best choice for a child who may try to open it alone. Ease of storage should not override the way it will actually be used.
Test the bathroom with the stool out and with it parked. Can an adult enter, close the door and move comfortably? Can the floor be cleaned beneath it? These ordinary checks reveal problems that a measurement under the sink misses.
Remove the stool when it is no longer needed or when unsupervised access creates a hazard. The aim is to support a specific routine, such as supervised handwashing, not to provide a permanent climbing aid to every surface in the room.