Wishing For Spring

I'm wishing spring would decide to come and stick around...and maybe kick winter out! And with that I've been thinking about gardens. This year the kids have asked to have their own flower garden. Since we have plenty of space, we've agreed. I know we can't get out to the yard to pick a place... let alone have any idea when we might really be able to put anything in the ground. But I thought I'd get them started on some inside plants... they need something to change things up in the daily schedule! (Cabin Fever is past dilerium!)

Any thoughts as to which flowers to plant? They are 2, 4, and 6 years old. I want something easy enough, but also (because of the younger two) something that won't take too long to germinate! Any suggestions would be great!