My daughter in-law stole my late husbands property, before the executor was able to do inventory what can I do to help the executor?

You can make a list of the property, real and personal.  The executor will need this for the Inventory and to attempt to recover it.  You can also offer to sign an affidavit that the step daughter was a guest, which may help the executor file a small claims or justice of the peace court suit to evict her.  While Colorado law and your late husband's will may give her an interest in the property, it is not hers yet.  If you are still paying for utilities, you might ask yourself why. Few people want to live without indoor plumbing, light and heat.