Night-time dryness isn't a skill you teach. It's something that arrives.

Daytime and night-time are two different stories. A child stays dry at night when the body starts making enough of the hormone that concentrates urine overnight and the bladder can hold it until morning. That usually lands somewhere between three and five, and wet nights up to five or six are still within normal.

The readiness sign is boringly simple: the nappy is dry several mornings in a row. Then you protect the mattress, put a potty next to the bed, leave a dim night light, and try.

Waking a child at night to sit them on the potty doesn't speed anything up. And an accident is laundry, not misbehaviour - no shame, no punishment, no commentary at 3 a.m.