Is it ok if my daughter can take dayquil she is 10 the age needed is 12 but it said ask a doctor she has sore thoat runnynose and cough

No, . No, it is not recommended due to the alcohol content in the medicine. There are gentler versions on the market that are made especially for children. Unless your doctor (who would be familiar with your daighter's medical history, weight, allergies) says its ok, the answer is no.
Medication question. I wouldn't. There are other medicines which are made more for children.