Get her the supplies and help her make a terrarium. All you would need is the soil, gravel, charcoal, a large jar and any decorative items. Then go shopping together for a few plants.

The large amaryllis bulbs you see in the store now are fun.

I don't know how old your child is, but kids like to chop the top off carrots, sit the piece in water and watch it re-sprout.

You sound like a very loving mom. Lucky child.

Fill box with soil as you would for any planting, then with the seeds- write your childs name or initials, cover lightly with soil, then cover with thin layer of rocks or glass, careful not to disturb the seeds.
Radishes work well because they grow fast. They will not mature enough to eat, but just pull them when they go by and write something else.