Day one did NOT look promising, my original plan was to clicker train her, just as I did with Honey and Kane (they also had no interest in balls). Initially she wasn't even interested in the treats, but i put that down to her nerves and persisted, we did 5 training sessions on the first day, the longest probably being 3 minutes and I felt like I had achieved very little, she was taking the treats but I could tell it just wasn't "clicking" in her head! Oh dear!
Day two was MUCH more positive! I ditched the clicker, as she seemed quite sensitive to it and used the word "yes" instead.... NOW she was starting to get it! I held the ball in front of her, she touched it, then looked at me for her treat... RESULT! Again we did 4/5 training sessions, each lasting no longer than 4 minutes, by the end of the day she was standing on her back legs to touch the ball, rolling it across the floor with her nose and following it around the room. 
In the evening I even watched her playing tuggy (albeit it with Darryl's sock!) with Jasmine, this was another break through as she is very reluctant to play with anything with other people/dogs present!
Cue big sigh of relief from me! It still is far from a n overnight thing, but I'm certain she will make slow but steady progress and we can reach our end goal!