Hi mate, that leaf at the bottom is shedding due to it being in the soil, nothing to worry about. I wouldnt give any more N as she looks to be well established in flower. They dont need a lot of N in flower.
I can see some spots forming on the leaves it looks like it could possibly be normal markings, it happens sometimes due to genetics. But with her being an outdoor plant if check her leaves (under as well) for pests just to rule them out.
Hope this helps 🙂