My sister is the "Personal Rep" for my mother's will. She did not divide the estate equally, per the will. Is there any action I can take?

Before the personal representative can distribute the assets of an estate, they must either obtain consent of the beneficiries or the court.  You should have been able to raise any objection that you had before distribution was made.  Did you have that opportunity?  I will also mention that the will governs the disposition of certain assets but not all.  It might be that the uneven distribution was proper because some of the assets distributed were not governed by the contents of the will. You should have an attorney review the details and give you a specific opinion.