One state will accept another state's laws and documents such as wills.
However-it would be better to have an attorney in TX to review the documents and
recommend changes(if any).
The answer given does not imply that an attorney-client relationship has been established and your best course of action is to have legal representation in this matter.
If the Will was valid in California, then it can be admitted to probate in Texas. It will likely cost more in legal fees and it might not function precisely the same way. I strongly recommend that she consult with an experienced estate planning attorney in the county where she lives.
DISCLAIMER: This is not specific legal advice and does not establish an attorney/client relationship.
I agree with the other attorneys. It really depends on the language. But almost always, spending a small amount of money getting a new ATTORNEY-DRAFTED Texas will (as little as 79 per will on sites like TexasWills.com), is far less than the price of trying to probate a will that doesn't meet all the Texas-specific requirements.
Kendall Cockrell is an attorney with The Cockrell Law Firm in Beaumont, Texas. None of the opinions he states on this site constitute an attorney-client relationship. For more information, contact The Cockrell Law Firm. Contact information available on Kendall Cockrell's profile on this site.
If they are alive and competent it would be a good idea to do Texas wills. Have a lawyer draft them.
Otherwise the California wills can be used here in Texas.
This answer DOES NOT establish an attorney-client relationship. This answer is based on the limited information provided and is not intended to be conclusive advice. There are likely other factors that might influence or change the advice after a more lengthy consultation.