geez. ok. so you are wondering what to do about the fraud? obvisously, the will situation is being taken care of with the probate. i am not getting a criminal connection with what you are describing this woman has done. has she stolen anything that is not legally hers, etc? the thing is if the will is in probate then the court will make sure everything is done properly. if you feel that she has things that should be accounted for and they are not - for instance, money in an account that her name was not on then there could be some criminal element. but it would be something that the probate court would handle along with the DA. you would need absolute proof of course, that something like that has taken place.
while it is very sad about the loss of your Father and the way this woman has chosen to do this it is not a crime for her, as his wife which makes her next of kin, it is not a crime for her not to tell your family that he has deceased. she should have morally or ethically but as a crime i am not making a connection. there is no obligation to have a funeral, either - not against the law. i am sorry. she should have followed his wishes, but she did not have to. the other thing is unless you can show the probate court that she intentionally was withholding the will and that it was not something that she suddenly "in her grief" came across, i do not know how you can prove intent.
again, if you can prove that she has stolen things that did not belong to her then you should make the probate court aware of your concerns. many times the adminsitrator of an estate will seek the advice of a lawyer, perhaps someone your Father was close to, for help in making sure the estate process goes smoothly because emotions run so high. in this case, she has caused you and your family extra pain at the time of this grief. there is a lot going on here and you really should think about talking to a local civil or estates and trusts lawyer who can make sure everything is done correctly and that all assets are accounted for. the police are not going to be able to help you with this
again, i am sorry for the loss of your Father