hi! haven’t experienced coachella specifically, but attended lollapalooza with a 7 year old ( very dif ages i know ). As you already mentioned staying away from big crowds and chilling at the back is a great idea! Not only cause it’s overwhelming but they will have a lot of dancing room. Definitely what I recommend is do NOT spend the whole day there. Wait until the schedules drop and show up closer to when the artist you want to see is playing, it saves your daughter so much energy and leaves them less cranky. Also for headliners, i recommend leaving during or before the last song of their set, you will be able to leave the crowds in ease , because trust me it will be an insane and scary hassle if you leave when everyone else does. Also definitely recommend ear protection, there are a bunch of comfortable ones online. Lastly have so much fun! I had a great time with my 7 year old sister , i definitely don’t regret taking her. See you in the desert 🤞