The most common way to avoid mosquito bites when outdoors is to use a citronella candle. Planting marigolds around your house can also discourage them from hanging around. You can likewise use citronella oil on your skin as a repellent.
For your child try using Yarrow tea. You can mist this on them to repel mosquito bites. This is a safe and affective way to protect children. Lemon Balm is an alternative to prevent bites for children as well.
Pure vanilla, believe it or not, actually repels mosquitoes. If you use imitation vanilla it won't work though. Mosquitoes are not the only bugs that don't like vanilla, so it's good to keep around. You can put vanilla on your pulse points to keep away the bugs.
Who would think that lavender, as wonderful as it smells, would be a natural insect repellent. You can use the flower to rub on your skin or use the oil on your pulse points just as you would for perfume. This is proof that you don't have to smell like a chemical to keep away the bugs.
This last suggestion might sound funny but by eating garlic, you will repel mosquitoes. Mosquitoes will not go near a field of garlic.