Woman on an island, day 28

I spent the afternoon looking for the right pieces of timber for my tree-house. I'm starting with the floor first. I reject a couple types of trees for being too flimsy or having insects inside them. I finally find a type of black wood that will work perfectly for me. I won't be able to cut down the whole tree but the branches seems sturdy enough to bring down with a little bit of planning. On my walk back I find some plant vines that have a almost rubber like feel to it, really strong too. I sit under the big tree, by a fire that evening and I start weaving the plant vines together. Now the question is: How do I get up into the tree? With a damaged leg and all? I look at the tool box and a small plan starts forming in my head...