Pullet wattles get red when they are near point of lay (POL). As mentioned each breed varies. But as a vague estimate usually around 4-6 months with some taking as long as 8 months.
These are 16 weeks. The pullet is on your left and the cockerel is on the right

The same two at five months. Look how the hormones are causing both sexes to develop.

This lovely gal is at POL at 6 months.

So is she, despite her smaller comb and wattle. However, note how red they are.

This girl, despite being 12 weeks older than the others, never did grow a large comb or wattle, but her red color indicates she is at POL.

Hope this helps!