Have anda ever noticed that almost all the relationships in Stephenie Meyer's buku have one partner significantly older than the other?

Just wondering if anyone else had thought about this. See, Edward is about 100 years older than Bella, Jared is 9 years older than Melanie, Carlisle is about 300 years older than Esme, Wanda is apparently several hundred years older than Ian, Jasper is about 50 years older than Alice, Ian is (physically) about ten years older than Wanda (who she's in Pet's body), Jacob is 16 years older than Renesmee.