Do you use a particular kind of whistle?
Sheba seems selectively deaf to whistles, unless I take a deep breath and make the pitch go up and down (like an air raid siren). I've got a shepherds whistle but haven't got the knack yet! Could do with some suggestions....
They will only respond to a whistle if they have been trained the basic voice commands first, or as in the case of puppies, the recall whistle is given every time the food bowl is put down. After four times a day for 5 weeks they know it means food. I use a 210 gundog whistle with a pea in it. But it doesn't really matter what whistle you use, so long as the dog knows the commands. I train 5 pips for the recall, 2 pips to turn
(whatever direction you are going in turn 180 degrees and go the other way)
and a single pip for sit, with a longer version of that for a forceful
'sit right where you are and don't move till I get there'
If you want to train Sheba to the whistle she must first know your voice commands. Start off in your own garden. Each time you give her a command to do something e.g. sit, blow the whistle command for sit at the same time. Then just use the whistle. When she is 100% at that then you can retrain outside. Then you can train the other commands. Dogs relate commands to specific places. if you train a dog to jump a cane in the garden using the command 'over' you can't take it to a field gate, say 'over' and expect it to jump. Some dogs will, but most won''t have a clue what you are talking about. It is a sad fact that a lot of people seem to think puppies come out of their mother's womb pre-trained. Not so, I'm afraid, it takes time, energy, patience, consistency and a whole lotta love.