Howdy Candi, and welcome to CPF,
First of all, good for you for taking the initiative and becoming proactive in beginning to develop a good self defense plan for you and your daughter. I'll have to pretty much agree with most of the folks here who are saying that a bright light is not going to be enough, but it's a great start, in that it will help lead you to a better plan.
I like the idea of the Tigerlight, and think that would be an excellent way to go for your immediate needs.
But I think the important thing for you to do in your situation is first of all, come up with a game plan with your daughter, and rehearse it... just like you would for a fire drill. Practice getting out of your house quickly, a number of different ways. Have a meeting place pre-established so that if you become separated you will know where you are to meet after leaving the house (maybe a neighbor's house?). Then enroll the both of you in a mother/daughter (depending on her age of course) self defense class.
I liked your thinking that getting out is the approach to take if at all possible. Confrontation should only be a last resort, but if you had to, then even a few well rehearsed self defense moves could save you and your daughter's lives (stomping on feet, knee to groin, etc), so even a short 1 day self defense class could be helpful.
If you do end up getting something like the Tigerlight, or any kind of pepper spray unit, the key to using it effectively will be in practicing with it until it becomes second nature, as you will have to react quickly if the situation for it's use ever comes up.
I hope you never have to use any of this, but at least you are taking the proper steps to become prepared.