The husband should promptly review the specific facts with his attorney to find out his legal options.
A decedent generally has the right to dispose of her separate property as she wishes.
An issue the husband should examine is whether "all her property and personal belongings" are separate property or community property. A decedent cannot give by will away the portion of the community properties that belongs to the surviving spouse.
Another issue is whether the husband is an "omitted spouse". An omitted spouse gets a share, specified by the statutes, of the estate.
"wedding ring given to the deceased by second husband" likely is a gift and therefore a separate property of the wife.
If everything was given to the siblings and the husband has no issue with that, daughter inlaw likely has no legal claim to anything, unless one of the siblings gets the jewelry and is giving the daughter inlaw the jewelry.
There are many missing facts. The husband should promptly review with his attorney before all the stuffs disappear.
Items acquired during marriage other than by gift or inheritance are community property, of which each of the spouses has a one-half interest. Deceased spouse can give away by Will only his or her one-half interest, not the surviving spouse's interest without that spouse's consent.
Items acquired during marriage by gift or inheritance are the recipient's separate property, of which that spouse owns it all. Deceased spouse can give away by Will all of his or her separate property.
The answer to your question will depend on how the now deceased wife acquired each item.
Richard Wills, WSBA 19720