Our own DaBird arrived in the post today.
We introduced her to it indoors briefly, and she went wild. Waited until later (darker outside, less activity, quieter) and took her and the toy outside.
She's now (after our 15 minute play session outside) standing at the door whining to go out ;-)
We heard not a single meow out of her while outside, when people walked by she noted them, but kept her eyes on the toy, and ventured all the way out to the sidewalk after the feathers. Wow.
When we came in after her last successful 'kill', she had her head up high and was trotting like the princess at the ball and has been cuddling with us since.
So maybe we just needed a stronger distraction.
As for Patti's and Deborah's replies, maybe you misunderstood me. We haven't been forcing her to do anything, or pushing her. She doesn't run and hide when the harness comes out, she stands patiently while it's fitted, and gets her treat when we come in. She comes in when she wants to. I just wanted to know what we could do to help her feel more at ease, and it appears so far that the answer is just to be patient. She does seem insecure outside, and skittish. Not this evening, which was nice to see.
I don't want to argue biology here, but imho a cat's natural environment is outdoors. Sure, many are acclimated to an exclusively indoor existence, but that's only in the last century if that. Maybe we should give them more credit and work with their biology and natural instincts rather than against? That said, I have no intention of letting her come and go as she pleases, but do look forward to playing more outdoors. Especially now that it's summer and nice outside (which only lasts for a few weeks before winter - and indoor weather - return).
Thanks again for all of the constructive comments.