YOU are not alone. My children are grown but I absolutely detested Science Fairs when they were growing up. It always seemed to get down to "the parents doing the work". The competition seemed to be between parents not kids! It was always obvious to me anyway that the winners had had lots of "help".
No, you are not a bad mom.......
p.s.---here in California, they study the history of the state and in the 4th grade--Most of the kids are required to make model missions---let's just say my opinion of the missions equaled my opinion of the Science Fair Projects