RECENTLY MY MOM PASSED AWAY SHE HAD A WILL IN PLACE THE LAST 2 YEARS,MY SISTER AN R.N. WAS MEDICATING HER WHILE SHE WAS IN A HOSPICE SITUATION AND

This sounds like it might be something very rare:  a real, provable case of undue influence, enough to have the new will thrown out.  I think you should talk to a local attorney about this as soon as possible, for a detailed review of the facts, including copies of both wills if you have them, or either of them.  That's the only way to get reliable advice.

Undue influence requires a showing that the person supposedly making the will was controlled by someone else, who had a confidential relationship and exploited that relationship for their own benefit.

I am a lawyer in CT and practice in this area of the law.  While competecy to change or make a will is a low standard (you simply need to know the assets you have and what you are doing/who giving them to), but here it sounds like there was some undue influence.  I suggest that you hire a lawyer to look into this. you may have to bring an action to invalidate the most recent will on the grounds of undue influence and litigate the case to enforce the first will.  You need to hire a lawyer asap before your mom's assets are dissapated.