There are several issues here:
1) Cold medications
don't work. There is not one single study that shows they are safe and effective for children under six. If you want to recommend something, recommend a vaporizer and saline nasal spray. If you are adventurous and the patient is not diabetic or an infant, you can recommend honey: half a teaspoon for children between two to five years, one teaspoon for children six to 11 years, and two teaspoons for children 12 to 18 years.
- Paul IM, Beiler J, McMonagle A, et al. Effect of Honey, dextromethorphan, and no treatment on nocturnal cough and sleep quality for coughing children and their parents. Arch Pediatr Adolesc Med 2007;161:1140-6.
2) I have no problem if you want to calculate the appropriate dosage of acetaminophen if you are sure you have an accurate weight.
3) Every pregnant woman is given a list of medications they are permitted to take. Ask if they have the list. It is safe to recommend acetaminophen as long as the patient does not have a liver problem.
4) You need to know when to refer and when you can help the patient self treat. If a two year old has fever but is eating, playing and otherwise OK, it is fine to treat their fever. If they are not eating or lethargic, it's time to refer.
You can't hide behind call your doctor because your are interested in protecting your posterior. You are or about to become pharmacists to help people, not protect your own ass. I don't think you will find a legal case where a pharmacist has been sued for recommending acetaminophen.