A round diamond is still a safe choice when you want something classic, but a completely plain solitaire can feel a little bare. Small stones along the band add more sparkle without making the ring look overly elaborate. For example, you could get her a ring like this https://pierrejewellery.com/katalog/ring-with-round-diamond-and-small-stones-on-a-shin-2965 . The round center stone gives it that traditional engagement ring look, while the smaller stones keep it from feeling plain. It has enough detail to look special without being difficult to wear every day.
