First thing I would do is get their roost inside where they can look out that window while on the roost. Might be good to have two bars for the roost (you should be able to utilize parts of that fallen tree for that). Next thing to do is get rid of the tree that fell, while it seems like a good idea to leave it, all you are really doing is telling them it is ok to roost there, and you sound like it isn't, that means it has to go.
The fence roosting is a problem, you need to make it uncomfortable for them to roost there. Chickens like a stable roost so fix the barbed wire so they will constantly wobble around if they try to roost there. That is the easy fix. The hard fix is to raise the fence height to over 8 feet. A chicken can make incredible jumps, some can jump 7 feet straight up, this makes it hard to keep them off unless you have the top of the fence higher than they can jump. Combine that with a wobbly feature and the girls will most likely find a different, more stable place to roost. That will be in the coop since you removed the fallen tree prior to raising and wobbling the fence top.
By the way, predators also hate wobbly fences, so they probably won't try to climb over more than a few times either.
Thank you!!! We will try to remove the fallen tree ASAP. And I will also try to floppify the fence some more!! Where they roost is where the barbed wire meets the chicken wire, and i think that gives them more stability. I shall remedy that!! Thank you for the suggestions!!