Have a picnic lunch on a blanket on the floor or in a den.
Get her teddies and dolls to go to teddy/doll school with her as teacher, or she can be the doctor or the vet and treat their injuries or illnesses.
Finger painting if you're willing to deal with the mess.
Do some tidying or sorting out of old grown-out-of clothes, with her "helping" (this will not help and you won't get the job done but it'll keep her busy).
Daytime bath with toys that don't usually go in the bath.
Make "potions" or magic mixtures or whatever, by offering some small pots or containers of different things for her to add and mix together.
Have a mixture of some dry pasta and rice and cereal and beans or whatever you've got, and see if she can pick them out back into separate pots.
Get a tub and add some plastic figures to it then top up with water, chuck in the freezer for a few hours, give to her with a wooden spoon to smash or some warm water to melt.