But to your question. The answer is...maybe. If they were leftover soap fragrances that you wanted to use in candles, I'd say yes, that's fine. But there are some candle fragrances that are not safe on your skin. If you look at candle fragrance supplier's websites, you'll see that a small portion of the fragrances are labeled "candles only" or "not skin-safe."
So...unless the bottle is clearly labeled "skin safe" or "for soap and candles" or some other language that clearly states it's safe for use in soap or bath & body products, I wouldn't risk it.
If there's no information, and it's from a major supplier, you could contact them or visit their website and check...but it's possible that formulations may have changed since your daughter bought it. The "cinnamon stick" fragrance that they carry now may be skin safe, but the one they carried four years ago (or whenever it was that they were purchased) may not.
Maybe this is just the opportunity to try your hand at making candles as well!
Here's more about the difference between fragrance and essential oils...
Mailbag Monday is a feature on the site where I share readers' questions and the answers. You can ask questions about candle making, soap making, or any of the related crafts that we engage in. Just email me with "Mailbag Monday" in the subject line.