What about the dogs, how you tracking them? Fencer: You might want to give the AVG and Lookout apps a look as well. However, the one Kenny suggested earlier, even though it's a pay app seems the most bulletproof.
Not sure this is exactly what you are looking for, but this is a friend's company. http://www.amberalertgps.com/ years ago he had a situation where his kid went missing and they were about to issue an amber alert. Works like a charm if you can cause your daughter to keep it on her person. If it just stays in the car or on her backpack/purse, and if something did happen, its going obviously just track the location of the tracking device, not her, and is essentially useless. But, if it actually stays on her, then this is exactly what you want/need. As a father of a 4 year old, I can only imagine the lengths I would go to protect my child..... Best of luck.
track the car... instamapper.com combined with a cheap motorola iden boost mobile phone... Do it right and you are going for ~$20 with $5-$10 every 3 months to re-up the boost account. You can hard wire it into the car pretty easily, she'll never know it's there and you can appear to be the trusting dad giving her space while not freaking out. Still ground her for not checking in of course but you retain your sanity. It was a great option I found after having 3 cars stolen... Let me know if you need advice/help on this option.
Get the Lookout app. It will locate your android phone using google maps. Works well... https://www.mylookout.com/features/missing-device
Thank you for the responses! The amber alert one with its devices reminded me that I have a SPOT sitting on my touring bike. I turn it on on when I go cross country riding to let the family know where I am. I know, I am sooo controlling, I want them to know I am safe when I take off for a 500 mile + day. If it comes down to tracking the car, (if that need arises), I may put the SPOT in the car since I already have it.