i first flew as an unaccompanied minor for melb to Cairns when I was 8 years old
i reckon i was just old enough at 8 to cope with the situation being on my own for 4 hours
yes the air hostesses were there, but they still wernt there ALL the time.

You run the risk of your 5 year old having to travel with other unaccompied children ( including other children up to the age of 11 years old) that may not be a good influence on your child as well. On my first flight i was with an older boy i remember and an older girl

Personally I would wait until she is just a bit older- I was a really independant, sensible kid and i reckon 8 years old was proabably the earliest I should have flown

btw i kept on drinking all the orange juice they gave me on my flight and as we landed i puked everywhere- all over myself and all over the person next to me
there was no one to tell me that i shouldnt- so i just did lol
i coped,but i was upset by what had happened and didnt have the sense to realise that what goes in has to come out. The poor air hostess had to carry me out of the plane with my clothes in a plastic bag and a blanket wrapped around me.

I would wait just a little longer or ensure that there was at least someone on the plane that she knew besides the staff- just in case

btw my friend has her kids go up and see their dad in qld from melb in the school hols and she flies up with them on the plane, and then turns around and comes back home the same day
She picks them up the same way and her kids are 10 years, 12 years and 13 years old and very sensible kids.

i would probably let my 10 year old twins fly unaccompanied together, but definately not on their own!!