I am not a doctor but I do work with animals and have two kids. Novox is an anti-inflammatory drug and the dosage prescribed for your pet probably would not cause any significant or long lasting side affect in your child. I would not worry at all.
Glad you called Poison Control, however, this is probably not the best source for an answer to a question such as that. You just never know who might react to what, especially when it comes to medication. Having had 3 kids myself, and had something similar happen, I was either at the ER or on the phone with their doctor.
Hope all will be ok.