Legal Question in Wills and Trusts in New Jersey

In theory, a Will is revocable (can be changed and/oir revised up to date of death), so what he has now could be changed at any time before he dies). This could be why she is denying you the right to see it now. Or, it could be becvause of the contents that she does not want you to know about now - good or bad. If Dad actually has dementia and cannot make decisions, perhaps someonme should apply to be his Gardian. The Guardian could see the Will and try to have it changed if there is anything improper in it.

You probably have no right to a copy of your father's will [it's his will after all, and the contents of the will are private, unless he elects to share them with you or anyone else].

In addition, if he has dimentia as you say, then the will probably can't be changed in any event [lack of capacity]. If there has been anything improper concerning the will [e.g. undue influence, lack of capacity when executed, etc.] then that will come out when the will is probated.