Please help. Using an old letter of recommendation?

This may sound silly but I was a teacher and then became a stay at home mom. Now I am going applying for teaching jobs once again and the school require letters of recommendation. My letters of recommendation (which are wonderfully written) are from 2000 and 2008. I also have one from 2004. One if from a teacher. Two are from principals. They are excellent letters. Now, I have been working part-time (have a good reference from that job) but it is not a school. Are these letters too old? I don' know who else I could get as good a letter from. Should I use the ones I have?