Traditional etiquette isn't always what's common for today.
It used to be traditional etiquette to only have a baby shower for your very first baby and that was it. Now it's pretty common for friends and/or family to throw them for any subsequent children, particularly if it's an opposite gender. Not saying that the OP is therefore required to throw one, it's at her discretion...but it wouldn't necessarily be out of order. It's not as if the intended recipient is going to throw a fit about having something done in her honor.