Golden is amazing paint and mediums. You are on a good track there. I've had hit or miss with anything Arteza. That just could be my bad luck, tho. Try to keep the colors in the room neutral, or white.
Since you're at Amazon, I went through my wishlist purchased area, and these are things I find useful for acrylic painting:
This type of palette saves paint. It goes in the freezer, and it can be used again and again. It comes in two sizes: Sta-Wet small or Sta-Wet huge
A Mister. I use it more than I ever thought I would
A large set of decent brushes half off for Black Friday Brushes
She also needs a fan brush, for happy little trees Fan Brush
This is extravagant (not a need, at all), but it's so good Paint Puck brush cleaner
And because brushes get a mess after a bit, this cleaner/conditioner General's
She NEEDS Gesso, Palette knives, Canvas pads (just make sure you get canvas , not canvas paper, if you don't go with these), and Varnish. The pads take up very little room, and she can do a lot of paintings on them, then mount them on frames if they are good. If not, it's not a lot of money out on a quality item. I also like Fredrick's in black. The varnish is used to preserve the painting.
A Sketch set to draw from a reference.
I really enjoy this Easel. It has wheels, so I drag it out on the patio when it's nice out.
(and a stupidly cute Brush holder?)
AND I wasn't kidding about the Color wheel With a limited amount of colors, she will have to learn to mix them, which is a GOOD thing.
Some kind of task chair with arms that lift, or no arms, comfortable enough to sit for hours. There should be some kind of table or desk in the room.
Edit: Because I walked into my art studio, and I like it a lot that you're doing this for her.
You dont need all this. Start with a set of pencils and the shading stick-thing.