
The quick answer is no, you don't need to have one thing on cue to teach another. You need to widen the goal posts, so to speak, increase her chances of success when learning new things by manipulating the environment or her to get it right. Put the tin somewhere where she can't avoid looking at it, and click and treat looking, build it up so that she will touch it, touch it twice, touch it 3 times, duration on the touch, one foot in, click for looking again, one foot in, two touches etc.
Keep your training sessions short and diverse, ie sits, puppy retrieve, "leave", and since she's HPR, mega solid recall!!! so that she learns to 'try' different things. And I would leave the down for a little while, if she's that confident offering it she's not going to forget it once you build it up again! I would be more inclined to spend training sessions on the more important life skills at this very young stage though I think, depending on the stamina of the dog, maybe she'll do more, you'd know her best :)
Short, diverse sessions, set her up to succeed :)