Hi,
At Kohl's (or even Claire's - but Kohl's are usually nicer) they will usually have some cute easter jewelry.... does she have pierced ears? You could get her little egg earrings and a necklace of a bunny or whatever.
or - they have those neat jewelry sets that have sayings... the "daughter" ones are nice. You could also get her a 'faith' necklace and a 'dream' ring and then write her a note that talks about the use of those two words and how they are relevant to Easter.
If she doesn't have any hobbies.... would she want to start one? get her an inexpensive digital camera (you can find them for as cheap as $20) and a scrapbook set that is easter themed (paper with eggs and bunnies, and pastel colors). Then ask if she would be willing to take pics that day and help her make a scrapbook of her pics - she can print them right off the computer on regular paper and put them in the scrapbook (or one hour photo at Costco or CVS is super cheap and you can do it right on line and pick them up in the store).
OR - give her a 'coupon' in her basket for a mani-pedi with you, but have the polish be easter egg colors. The nail techs would be happy to paint each nail a different 'easter egg' color. Plus - it's bonding time for the 2 of you. We have been to Pinky - they have salons in a bunch of places now. or Arbre downtown is great... I would recommend either place and they are both good with young ladies.
Good Luck!