Baby steps my dear.
I'd start with clicking for a curve towards the tail, then maybe a nose touch? Teach her to nose target something, then stick it on her tail? Then raise the criteria to putting her mouth around it. Basically, train it like you'd train any type of retrieve...just the turning to get the tail would be non-retrieve part.
I saw a video of Debi Davis' BC service dog at Clicker Expo...he'll retrieve and hold his own back leg...(lying down). I started with Score...but kinda forgot that I was working on that until now...
. I've also been slowly working on having Score retrieve my hands.
Sorry, I had a beer tonight...now I'm rambling.
"I don't have any idea if my dogs respect me or not, but they're greedy and I have their stuff." -- Patty Ruzzo
"Dogs don't want to control people. They want to control their own lives." --John Bradshaw