You are required to receive an accounting and a K-1 for your distributive share. You should ask for a copy of the tax return, even if you do not have an absolute right to receive it. Most the time a trustee will provide it to you upon request.
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.
You should definitely consult with a probate litigation attorney. Trust beneficiaries generally have more rights than they realize. It all depends on the trust instrument. Sometimes, that will provide that the beneficiaries are entitled to statements of account, or perhaps additional information. If there has been mismanagement of the trust assets by the trustee, or the terms of the trust have not been followed, you could have an action for breach of trust. Please feel free to let me know if you would like a consultation. Best of luck, Rabeh
Please note - I am providing you with general comments, not legal advice. Nothing in this answer creates an attorney-client relationship nor constitutes legal advice, as I do not know the facts of your case well enough to be able to guide you, nor am I making any promises about the outcome of your case, or any guarantees about my capabilities, skill level, or predicted success. If you would like to retain me to provide you with legal advice, please contact me and we can discuss the engagement.
It never hurts to get a real attorney involved to look over the situation. With the amounts at stake, it is like a form of insurance.