My LO is 12 months and her nose had been super runny. When she was 6 months she had a bad cold and they told me to give her 0.25ml of Children's Benadryl. The box says 12.5mg/5 ml. 2.5ml is 1/2 tsp. the syringe goes up to 3ml

The nurse said to give her 3.75 ml which is 3/4 of a teaspoon. That seems to be a huge jump from before and I'm nervous exceeding the syringe value. (I know id just pour it into a teaspoon but still) Is that dosage nuts or am I being a crazy over thinker mama again