What is the protocol for trimming your neighbors trees?

My neighbor’s trees, on her property, are hanging over her fence and actually laying on top of some of the utility wires coming into my home… It looks like my electricity, phone and cable wires are all being affected. They are pressing down on these wires pretty severely and need to be trimmed back. My assumption is that the tree trimming will be her responsibility, but I want to make sure that I am correct in this assumption. Our neighborly relationship isn’t all that neighborly, she has complained often about activities on my side of the fence. In my opinion, she has not been very reasonable, I would describe her as the prototypical crazy lady next door.