Question Plugin items don't show up in Creative Mode. Normal or no?

Disclaimer: I am very new to this. I'm sorry if this question has been asked, I searched and found nothing.

This is the first time I've ever tried to make a server. It's mostly intended for my niece and nephew - so I'm just experimenting with different things and not really feeling pressure to get it perfect. I'm doing pretty good, learning as I go.. etc etc. But there are some things that I'm not sure are normal or not..

I managed to install a plugin last night that added a bunch of items, and all plugins are functioning properly as far as I can tell - except none of the new items show up in Creative Mode. Is this normal and intended? If so, is there any way around this - such as a plugin or a permissions/config - that would add these items to my Creative Mode? I will bear the burden of manually crafting these items if I must - but I'm trying to create a nice little world so it will be a pain

 

Are these "new items" custom bukkit items? Or like a mod (real NEW items)? If they are created by a plugin, they aren´t available in creative mode as far as i know.