My daughter &son weregiven amoxicillin for strep in august, my daughter has become sick again so i gave her this med (exp shows 2014) is this ok?

No: Most illnesses in kids are viral. You should never start antibiotics unless a doctor diagnosis your child as having a bacterial infection (as was the case with strep throat). Over use of antibiotics is harmful to your child (resistance, side effects, disrupts healthy gut bacteria, etc), and will do nothing at all to cure a viral infection. It would be best to see your child's doctor at this point.

Bad idea : If it was a liquid med, it begins to deteriorate as soon as water is added and Amoxicillin is no longer good after 2 wks in thr refrigerator or 1 week at room temperature.(no matter what the expiration for the dry powder). If a pill, it would be still in date, but without a proper test proven strep, the treatment may be wrong.If mono, you may be rewarded with an interesting rash.