You've got the makings of a Will Contest, if your mother's other children have anything to say about it and the desire to engage in probate litigation. There's nothing that prevents you from offering what you believe to be the actual Last Will and Testament of your mother. That said, erring on the side of caution in your case might include depositing (but not filing for admission to probate) the later-dated document. In any event, if you're going to hide something, (and I wouldn't necessarily encourage it) I'm not real sure that you want to publish that intention in a public forum like this.
Photocopies of Wills are permitted admission to probate in Texas, but only if some additional requirements and proof are met. First, you'll end up having to notify the individuals that stand to inherit by intestacy as if your mother died without a Will. Second, you'll have to prove your diligence in searching for but not finding the original.
I'm not quite sure how you know that the second document is a forgery, unless you were there when it was not signed by your mother. But you can bet that as soon as your siblings are notified of your intentions to offer the first document, they'll claim that the second one is legitimate. All said, you really need to sit down with a probate attorney in the county that your mother resided in at her death to discuss these issues.
This answer does not constitute legal advice. I am admitted to practice law in the State of Texas only, and make no attempt to opine on matters of law that are not relevant to Texas. This answer is based on general principles of law that may or may not relate to your specific situation, and is for promotional purposes only. You should never rely on this answer alone and nothing in these communications creates an attorney-client relationship.
I cannot advise you to keep "hidden" any document that may be a will. I understand that its provisions appear to you to be the same as in the prior will, but that may not be so.
If your mother was not married at the time of her death, and if you are the only child, you may petition to administer her estate in intestacy, and you would thus be the sole beneficiary of any assets that were not jointly held, held in trust for another person, or held in an account with a designated beneficiary.
If that is not the case and if you would be better off pursuant to each of the wills that your mother may have executed, you can present those documents to an attorney and see what advice you receive. In any event, you should promptly consult an attorney.
Good luck to you.
You should promptly consult with a local attorney.
Michael S. Haber is a New York attorney. As such, his responses to posted inquiries, such as the one above, are limited to his understanding of law in the jurisdiction in which he practices and not to any other jurisdiction. In addition, no response to any posted inquiry should be deemed to constitute legal advice, nor to constitute the existence of an attorney/client or other contractual or fiduciary relationship, inasmuch as legal advice can only be provided in circumstances in which the attorney is able to ask questions of the person seeking legal advice and to thus gather appropriate information. In addition, an attorney/client relationship is formed only by specific agreement.