What happens when Schedule K-1 not provided?

The attorney, who is executor of an estate of which I am a beneficiary, has not provided the K-1 I need to finalize my return. I filed for an extension when it became obvious that the K-1 would not arrive in time for the April 15 deadline. It is now plain to see that she has no intention of providing the K-1 before the October 15 deadline. Do I need to do anything at this point, or do I just let the deadline pass and then file an amended when the K-1 eventually arrives?