Graphic art pad versus iPad pen and drawing package?

[fourelementary]

Dd (14) is into her art and enjoys using her iPad and pen to create digital artwork. Would a graphic pad thing add anything extra? And if so- any recommendations?

There is no point buying a pad because the being able to draw on the iPad itself directly is far superior

I don't know what a graphic pad is but all she needs is the iPad and one or two software apps, eg procreate, photoshop