You may be confusing executor and trustee. The trustee is the person responsible for the trust and the executor is related to the Will. They may also be the same person. This is an area that should have an attorney involved on your side. If you bring a contest and there is a no contest clause in the trust, you could lose your entire inheritance if you do not prevail in the contest. An attorney can also review the situation and determine if a contest or some other action should be taken. Dishonesty by the trustee can lead to removal and replacement of the trustee. This requires a petition to the probate court.
Any individual seeking legal advice for their own situation should retain their own legal counsel as this response provides information that is general in nature and not specific to any person's unique situation. Circular 230 Disclaimer - Advice given in this response cannot be used to eliminate penalties with the IRS or any other governmental agency.
If Auntie is making decisions regarding such things as which assets should be sold to pay for the costs of administering the estate or paying creditors, it is unlikely that you have much of a case. She is entitled to make independent decisions about those sorts of things.
If you can show that she is being dishonest, using the assets as her own, making special deals for her family or friends, or the like, you have the right to contest her actions. She could be personally liable for the damage to the beneficiaries of the estate.
If you feel the trust is drafted in a way that your grandmother really did not intend because of the undue influence of your aunt, you must proceed with great caution. This is the instance in which the No Contest clause may take effect. If you lose this action, you risk losing anything you may otherwise have inherited. That is not to say you have no ability to sue; it is just to point out that you had better not only be secure that you are right, but that you are prepared with solid evidence because the consequences could be severe.