My girlfriend is at level 31 and has never found a carry weight item to disenchant. Anyone know where she can find an item in a permanent location or are they all radiant items?

You can find out about all the "fortify carry weight" possibilities here:

http://elderscrolls.wikia.com/wiki/Fortify_Carry_Weight

The information includes a list of items enchanted with "fortify carry weight" that you can disenchant. I hope you find the answer you need.


Edited to fix typo

There is an invisible chest in Dawn star http://www.youtube.com/watch?v=RCvxYe5LqY4 just hang out until an item with fortify carry weight spawns in the chest.

I have always found a set of leather boots in Sinderions Shack in Blackreach, and the Revelers will give a Charmed Necklace when they are offered some of a characters Honeybrew Mead.

This. These guys are always dancing beside the road and I usually find them at level 1.

I usually make rounds on blacksmith merchants, they tend to carry a few enchanted items. I caught a merchant in Whiterun with a +Carry item, so I snatched it up.