This will depend on what the Trust says. Often times, the trust says that upon the death of the first spouse, that the estate is divided into a Survivor's Share, and a Decedent's Share. The Decedent's share is irrevocable, typically allowing the surviving spouse to be the Trustee, and the income beneficiary, but cannot deplete the principal. If this is the case, you are to have been provided notice that this trust is irrevocable, and given a copy of the Trust.
If the Trust allows the surviving spouse to have everything, with no restrictions, then you would be out of luck.
Regarding the Jewelry, similarly, if the Trust does not have language in it that specifically gifts the jewelry to you, but has language that the surviving spouse keeps everything, you would be out of luck. Personal effects often are the toughest things. You could open a Probate for the personal effects, forcing your step father to have to defend himself as to why he should keep them, producing the Trust in Court.
Not sure this helps, but good luck
Sorry for your loss. As a beneficiary of your Mom's trust, the Successor Trustee, [may be your step-father] should provide you with a copy of the trust. Also if your Mom had a Will [assuming again that your step-father is the executor], he would have to probate it. When he files for probate, usually an original of the Will is filed, so you can get a copy from the court, if you cannot get one from the executor.
The Trust and Will shall determine the disposition of her assets. Assets purchased during their marriage is considered community property -- so generally what this means is that 1/2 of the asset belongs to your step-father and the other 1/2 your Mom could bequeath as she wished.
Again it is all dependent on what is in the documents.
It is highly recommended that you consult with a local probate attorney for assistance.
AVVO or the San Joaquin County Bar Association can provide attorney referrals.
I agree with Mr. Mchugh. If your mother's share is irrevocable, you are entitled to a copy and will be entitled to receive the assets in that trust after her husband passes. If the entire trust is revocable, he can change it and leave everything to his kids. It is a very unfortunate reality.