If her weekend is anything like the festivals I used to go to it will go a bit like this.
Arrive early on Thursday (after rubbish nights sleep due to excitement and early rise). After long walk with heavy rucksack set up camp. Go to bed late, 1am ish and struggle to sleep because the crowds are yelling bollocks and the only sound proofing you have is the canvas of your tent.
Wake up at 6am on Friday because the sunlight is very bright through the canvas. Stay up till 1am again (very hard to sleep because festivals are so noisy). Wake up at 6am on Sat.
Saturday night will be the same in bed by 1am at earliest and awake by 6am.
Just the lack of sleep is exhausting but you also have to walk miles everyday and do lots of dancing. Plus the showers are virtually unusable so the last time she will have showered will be early Thursday morning.
It sounds like the plan would be to pick her up after the last band on Monday night. Band finishes at 11pm (this is optimistic). It will take at least 45 minutes to get from the arena to her tent and there will be a mad crush of people.
She will need to get her stuff and walk out of the camping area to a road to be picked up. Again being optimistic this will take 45 minutes.
So she will be picked up at 12.30am at the very earliest. It will then take 1 hour to get home and she will need a shower when she gets in at 1.30am. So the earliest she will be in bed after an exceptionally exhausting weekend is 2am.
Not sure what time she will need to get up at for the ceremony but probably 7am.
Am just remembering how shattered I was after each festival I went to, I always took 2 days off work to recover and could have done with longer.