Wondsor and Newton inks and lots of brushes (one for each colour). Don't bother with silver or gold. Needs good thick watercolour paper.
Big arty marker pens (different tones) and A3 or A2 pad of paper.
We don't rate any of the coloured pencils, watercolour pencils are a total waste of money and space.
Try a pack of watercolour wax crayons, can add interest.
If you have somewhere well ventilated where she can work and space to store her work while it dries, oil paints at the best of mediums. She'd then need canvases (can be small) and special brushes (can also be small). If not, just don't get these as she should be able to use them at school/college.
Drawing pens in black and sepia are great tools if she likes to work small and enjoys line.
Charcoal and pastels are great for those who are interested in light and shade.
Pencil sharpeners. An electric battery operated one is a boon.
You could get her a 'stay wet' paper palette for use with acrylics as they tend to dry out very quickly and it helps avoid wasting too much paint. Get extra brushes as acrylic dried on a brush ruins it.
Printmaking equipment (lino tools and lino sheets - the see through acrylic ones are great) and rollers and lino ink, if printing and colour blocks are something she'd enjoy.
She will need a portfolio or two.