Can my girlfriend have the right to be on my child's emergency card, even thought my current wife and I not fully divorced

No, she cannot. She has no legal rights regarding your child. She cannot take your child to a doctor. She cannot make decisions for your child. She cannot be part of any education/school decisions regarding your child. Only you and the mother have those rights.

I disagree with my collegue, however it would probably require the consent of your exspouse to be and she should be able to designate someone else to. The real question is what happens when there is a serious injury and neither of you can be reached or are far away. A fireman, paramedic or trip to a hospital may be required and emergency treatment will be given. But for a boo boo, a school nurse is sufficient. Think about and if you and the ex can not agree, then too bad for the child and be fair what is good for the goose is good for the gander.