Lightest 40°F synthetic sleeping system (quilt/bag and pad) for warm-weather hiking with a child?

Hi guys, I'm planning on get into long hikes in warm states with my 6-year-old daughter and need advice on ultralight sleeping systems. My priorities are:

  1. Lightweight gear (to offset extra food for my child)
  2. Compact when packed (I may have to carry 2 sets)
  3. Durable
  4. Synthetic fill (40°F rating) (ethic reason )

I've already acquired a Hyperlite backpack(got it basically for free with credit card rewards). Looking for recommendations on:

  • Sleeping bag or quilt
  • Sleeping pad

Should my daughter use the same setup, or do you have alternative suggestions for a 6-year-old?

Any advice is appreciated!