Orange cookies ... attempt number 2

This girl was doing amazing .. a week and a half ago she was green and full and would spill out of the tent when I'd open it up.. .but she turned yellow and her leaves burned up and fell off suddenly. I'm giving her nutes and it's affecting another plant in the room so the only thing I wasn't controlling was the ph... so I am buying a kit I have a soil reader and brought the soil down a bit and hope that does the trick. Then I fed a little too to make sure they could absorb the nutes. Hopefully she rebounds. I'm kinda sad seeing her like this.