dj wrote:
My darling 2 year old is loving gardening at the moment. She loves
watering plants and watching them grow. (She also loved pulling up the
tomato plants we had planted together and running around the garden
with them...)

She also loves flowers. Picking them that is.

I thought the best plant for her would be something which grows fast,
and has lots of tiny flowers. Preferably in a pot.

Alyssum, or however it's spelt. That's what my dad started us off with.
Alyssum and nasturtiums.