Ours was about the same age the first time we took her. The headphones/ear muffs were a saving grace, we were up by the stage during Trampled By Turtles and she slept through it all. A baby carrier was a blessing as well, I was able to "wear" her when she got fussy and just wanted to be held (so we didn't have to miss Sam Bush) We didn't have a wagon, we just used our stroller but a wagon would have been easier. Don't forget things to keep the little one busy, luckily we were with a group of parents that knew that and had enough toys to go around. Food, hydration, sunscreen and a hat. Clothing, layers..... it was really warm during the day, she had shorts and a tank top on and as soon as the sun went down she needed to be bundled. Hope that helps, we had a blast and didn't have any major issues taking a 7 month old. Little mittens or gloves will be handy too.