I think she was close to being overfed but not by a lot, just a little. I wouldn't think overfeeding is the issue on the bottom leaves because your upper leaves look so good. Hope it is nute spill like Da Mann says. I think switching to water only for a little bit is a good idea, especially if you had hot soil to start with.
I have been sure not to pour the nutes on the leaves. It's been just water fur a week and a half now. I'll be careful with the nutes and see what happens