Gift for Boss

My boss and I have a good working relationship and friendship. His daughter is about to give birth to a little boy and I would like to buy the baby a small gift such as a blanket or outfit. Normally I would gladly buy the gift and not think much of it; however I have been told his wife is a very jealous person and does not appreciate females having anything other than a professional relationship with him. I find this silly, because he is almost 30 years my senior. My question is "Is it appropriate to buy a baby gift for my boss's new grandson?"