Dude, calm down. She was just giving her opinion, an opinion I share. I am from the Midwest and yes it would be weird if someone did that here. No one is saying you shouldn't donate to a cause that is close to your heart. I guess what people are saying is that a baby shower that you are hosting for someone else might not be the most appropriate to do so. A donation made to say a memorial fund of someone close to the MTB wouldn't be too weird, but yeah just picking a random charity would be.
Again, no one is saying you shouldn't donate to a cause, but what might make people uncomfortable is being so public about it.
Oh and I know this is totally off topic but I love your pic. We also went to Disneyworld in the fall time and loved it. Can't wait to go back.