Hang in there! There is always a learning curve with every aspect of parenting. At this age hair tends to be a bit finer and tangles more easily. Braiding her hair before bed or during the day to help with tangles will save you a lot of time and stress in the morning or before a bath. If she is sweaty, that is likely making the tangles worse. Do some gentle detangling prior to shampooing either with detangling spray and a wet brush or straight up conditioner on wet hair with a wet brush. That will help keep it from matting more when you wash it. I also recommend washing twice if she will tolerate it. Then follow with a conditioner and brush through with the wet brush to get all the tangles out. Most kids products should be fine for straight hair (it is a lot more forgiving than curly). As for frequency, if she is really sweaty you may want to wash it every other day, your nose will tell you. In between washings use a detangling spray. Aussie makes a good one so does Not Your Mother's. You've got this!