It looks like asian bush honeysuckle to me. It has small honeysuckle flowers in the spring and then red berries now. If your sister waits long enough it will probably show up in her garden on its own, it's considered invasive in PA and I rip it out here and there each year before it gets too out of control.
Frank

Here is a link that might be useful: bush honeysuckle

NO NO, you don't want it!! Nice as it seems to get a bush for free, and they do smell nice, they are a horrible, horrible plant to control and get rid of once they have invaded a natural area. They will take over your hedgerow. They are leggy too. There are other more well behaved bushes you can get--Winterberry holly comes to mind as a plant that has similar gorgious red berries in the fall. Some of the vibirnums also have red berries, and Vibirnum carleseii also has fragrant blooms. There's also red currants, cottoneaster, and highbush cranberry for red berries. Even pyracantha, although that has thorns. AVOID like the plauge euyonomous and japanese barberry, they are invasive too. There are so many other wonderful options!

If you want something that smells nice, try clethera, or some of the native fragrant azaleas or rhododendrons, like your native Carolina rhododendron. Other fragrant options are some of the witch hazels and fothergilla.

Here is a link that might be useful: Winterberry holly

Let's see, it's beautiful and thriving? Of course, it's a horrible invasive! Why is that always the case?

For what it's worth, I've got one of those in my hedgerow out front, and it hasn't taken over in the 9 years I've lived here. This year was the first time I've ever seen it bloom, actually.

And even though it's an invasive, those berries are probably a decent source of nutrition for birds.