Keith, here's a picture of 4 of my Phals. See how they are facing sideways, not straight up? It's pretty important to place the plant that way in the pot so that water never sits in the crown of the leaves. Also there are 3 good examples (and one bad one) of pots for them. Holes in the sides of the pot are important, or you can mount on a piece of wood or (in my case_) a palm boot. That's not the best way for one that's going to be grown indoors, though.
As Tarev said, start with some orchid bark mix and a pot with holes. Dump that baby out, and trim away all the roots that are brown or beige or squishy. Healthy roots look like those sort of shiny grey ones, or white and spongy. You don't need to bury all the roots when you repot, either. The plant will grow roots up into the air because that's what it needs.
I would see if there's a better place for her to grow that plant than the drafty windowsill. Phals like indirect light, not direct sunlight so it doesn't really need to be that close to the window. A tray of pebbles under the pot with water in it (not touching the bottom of the pot) will supply some extra humidity and I also spray the leaves of mine with a fine mist of plain water at least once a day when the humidity is low - and it almost always is low indoors.
Don't worry if it doesn't bloom this spring, it is recovering and needs to grow some new leaves before it will bloom. Next spring will be it's time. Btw, patience is a huge virtue with growing orchids. They are really slow growers, most of them.
