Baby Shower, should I help or not?

It is considered rude to have a 3rd (or 4th) baby shower. One is fine and if a second one is needed due to a different it is supposed to be a "sprinkling" What more could she possibly need unless she had 3 boys and is now having a girl? I would say it is considered tacky to have one for every child and say you will attend but since you did the last one they can "have at it" this time.