I agree, start her out simple with something that is obviously hers. Nothing says "I'm a little girl's fishing rig" like a Barbie or Dora rod. Buy an extra for her to practice with around the house.
As they graduate/grow, the problem does become a little more complex. My girl is 8 now, and the battle I've been fighting is finding gear that fits her, yet is robust enough to land decent fish without undue wear and tear. Zebco 33's just don't last that long when in schooling Tawakoni hybrids. This year she'll graduate to her first spinning rig and we can start getting a bit more serious.
But for starting out, yeah, keep it simple. And, make sure whatever she's fishing with will float, or attach a rod float to it. The last statement, I speak from experience.
If you're not living on the edge, you're taking up too much space!