Yes, you can give Advil to a 7-month-old baby for teething if Tylenol is not providing relief. It is recommended to give the correct dose based on the child's weight. You can alternate between Advil and Tylenol every 3 hours but always wait 6 hours between doses of the same medication. Remember to keep track of which medication was given and at what time to avoid giving the same one twice in a row.