Hi Steph, and welcome to the site. We need more information I'm afraid - I see you're in the States, can you tell us your USDA zone please? If not, we need to know where in the States, not your address, just the area, so maybe San Francisco or wherever.

Also need to know whether these plants will be in shade or sun, or partial shade, whether they need to be ones that tolerate drought conditions or whether the soil (dirt) is damp, or you'll be irrigating.

Regarding 'safe' plants for children, more than 52% of plants grown in gardens/yards are toxic if eaten, so although you wouldn't choose to plant something with, say, poisonous but attractive berries, or a skin irritant plant, with children about, its important you teach your children never to pick and eat anything in the garden, or all you'll be growing is things like lettuce and cabbage because they're safe.

As you mention plants that can go indoors or outdoors, does that mean you won't be planting anything in the ground, it'll all be pots?

There are packets of seeds designed to interest children
in gardening. I remember my first packets from Woolworths. Most exciting.

For children I think nasturtiums take a lot of beating. They are tough and they spread long trails around, and they have so many flowers that the children can pick as many as they like. You can pickle the seeds for capers and add cut up leaves in salads. They attract cabbage white butterflies so the children can see both the butterflies and caterpillars, and with luck watch over a chrysalis over the winter, as long as its in a cool place, and watch the new butterfly emerge.

That was my first plant, 50 odd years ago!

My first was Virginian Stock.