My kids could play for ages with the little puff balls you can get at the craft store - put them in a dish pan and give them some measuring cups and bowls and they are happy as can be.
Matchbox cars with a little town/road mat.
Playdoh or kinetic sand.
Dish pan filled with soapy water and some small toys, some that float and some that sink.
She might like if you built her a little fort where she could take some stuffies and play. Build her a small incline out of a board or piece of sturdy cardboard and give her a few things that roll.
Pile of fabric scraps to dig through.
Tape a huge piece of butcher paper to the floor for her to color on.
Little bags of dinosaurs, farm animals, fairies, jungle animals, etc. and a basket or bucket with a handle so she can carry them around
Sorting bears (or anything she can sort by size, shape or especially color into cups/bowls of the same color - could use the puff balls from the first idea to keep it cheap).
Pattern blocks, you can get either a big tub for free use or you can get them in a set with designs for her to build on (many are simple enough for a new three year old). Beads to string.
I've seen some lacing cards that are basic enough for a new three.