Can I write a direct letter to a probate judge with information about an upcoming hearing?

My friend died recently at age 96. She left no husband, no siblings, and no children. At niece of her deceased husband gained her power of attorney about 2 years before she died, and may now be attempting to be executor of her estate. My friend never has trusted this niece, and confided her distrust to me about 5 years ago when she was in good health, and also about a year ago before the niece threatened me with a restraining order if I visited my friend. She wished to leave her estate to animal protection organizations and not to her niece. How can I let the judge know that was what the will was supposed to state? The county clerk has given me the case number and the judge's name. As of last week, the hearing date had not been set.