If they weren't pollinated they would not become hips and there would be no seeds. There are some roses that are not fertile so don't produce hips. Not knowing what roses your friend has I can't say if it's one of those or not.

It is a "peace" rose. It is yellow on the interior petals and pink on the edges. It was bought at a local hardware store.

Setting seed is pregnancy. If the plant is stressed, it may not set seed. If, for some reason, the pollen didn't make it to the pistles to accomplish fertilization, or if the weather was not conducive to fertilization (too wet, too cold, too hot, etc.) seed won't be set. If the plant is too immature, it may not set seed. Just as with people, "getting pregnant" is hit and miss. Some are more fertile and willing to set seed than others. Those of us here in extreme heat areas quickly find out how late in the heat we can pollinate before it stops working. A friend out in Rancho Mirage, near Palm Springs, has already stopped pollinating because it's too hot for fertilization to work. I'm still pollinating here just north of Los Angeles because it's still working. If I allow the seed parents to dry out, they'll stop setting seeds. If I don't watch how I water and the pollinated flowers get soaked by the hose, fertilization might easily be stopped for those blooms. If your rose fits any of the mentioned categories, it could explain why seeds didn't set. Kim

Thank you very much. I'll keep those things in mind. I didn't keep track of the weather but I'll give it lots of water and fertilization if needed. :)