I did field hockey, indoor, and outdoor track in hs as well as all-stars. I never had any issues. It was a lot of driving and long nights doing hw in the car, but I wouldn't change it. I made sure both coaches had copies of my schedules. My school sports were done practice at 430, and games sometimes 530/6ish. Cheer wasn't usually till 6/7 ish and was about 20 mins away so that gave me plenty of time to transition. I did have Sunday night practices for field hockey which would sometimes overlap, but since that was in the fall (aka pre-comp season) and they'd only overlap by like 15-20 minutes my coaches were okay with it.
However, I coach hs lax now and would make my kids choose one or the other. We have weekend practices for Monday games which would conflict with competitions in March/April and our practices are typically until 530-6. Being in NH, we have to travel upwards of 1.5 hrs to a game occasionally so may not get home until 9ish. I wouldn't keep a varsity player who may have to miss some of those games and leave practices early, JV I would consider, but with the understanding she may not get as much play time and might never move up to Varsity. Since she's so young though, I'd say do both for now and see what happens. Her interests may change and she might decide to do one, or the other, or none, ya never know!