A photo would have been useful, but to be honest, it doesn't sound like it needs feeding, it sounds like it needs a thorough soaking, and then watering deeply and regularly when it needs it, which, if the plant is new this year, will be easily weekly in hot weather. Can't say how much water you should give it weekly without seeing the size of the pot, but a basic guide is 2.5 litres - any excess should run out the bottom. If the rootball has dried out, its quite difficult to get it wet enough again, so if you haven't done so already, saturate the plant. I'm assuming the pot has good drainage holes which aren't blocked. Note that feeding whilst a plant is suffering drought is a waste of time and money, the plant cannot take it up and make use of it... and permanent plants should not be fed past July anyway.

Once you've sorted out the watering, wait a week or so and, if the plant recovers, then snip off any obviously dead parts.

You say she planted it recently - did she move it on from a smaller pot or was it dug up from somewhere else? It is often a strain on plants to be transplanted in the middle of the growing season so that might have been a contributory factor.
Or if you have in fact been watering it very regularly perhaps the opposite of the above might apply and it could be too wet and drowning? Unlikely but just possible.

The plant is going through transplant shock. Fall is the best time to transplant. The hot weather doesn't help either. Keep it watered, it should recover in a few days. Don't prune it or anything, just leave it be & keep the soil around it moist. It should be fine in about a week.

Erm, can I just point out, guys, that this plant has not been planted into the ground, nor transplanted as such - it was merely put into a larger and presumably more decorative pot (hopefully into ericaceous compost), placed in full sun and then given insufficient water by the sound of it...

Also, azaleas need acidic soil or they won't be able to take up nutrients.

I don't think the enquirer actually said where it had been moved into the pot from? I was hedging my bets there.

That's true. Those pots dry out quickly and azaleas need consistent moisture and bright shade - dappled sun.