Hair children aren't showing in particle edit mode Can't display children hair from particle edit mode as it is shown on this famous video at 1:40:
Blender Hair Tutorial Part 1 (styling the hair)


I have to go back to the object mode so the additionals spline appears.

Is there any way to display the extra hair directly while editing?
You have to enable the children option in the top right corner of the window before painting your strands, then the preview is working: