Whippet Mix: Can You Tell by Appearance ?

I have 2 sisters that are just over 2 years old and when I adopted them, I was told they were Whippets.

Well, a Whippet doesn't get to be 48 lbs or 60 lbs, so I am trying to get a better understanding about what they may be mixed with, so I can find a good weight that they should be at.

Both dogs have their own characteristics, one is normally smaller than the other.

I am hoping that someone may see what they are mixed with by their appearances, I was told it could be either, greyhound, collie or a borzoi, what do you think ?

NOTE:

Interesting puzzle. Please, try again to send the picture!