1 wk post closed rhinoplasty and sister accidentally hit my nose. How likely is silicone implant to dislocate or move?

Hello and thank you for your question, At one week post-op, I would contact your surgeon and schedule an in person evaluation. This is the only way to know for sure if there is any implant movement or trauma that may impact your final result. I hope this information is helpful and I wish you the best of luck. 

While you can dislodge and move silicone implants on the dorsum, you will immediately notice it being crooked and your surgeon can move it back to where it should be.  If it looks straight now, chances are it's fine.

Since you are only 1 week post op, it is likely the graft could move.  Avoid nasal injury and trauma during the healing process. Absolutely, I would visit my surgeon for an evaluation.