One of the best (and worst) things about having more than 1 child is the relationships they form. Obviously sibling rivalry is not on the top of my "best" list. Sibling rivalry probably does have some advantages, like teaching negotiation skills (or self defense). There are some relationships that fall on the "best" list though.
The relationships I am talking about are the bonds. When you are cleaning up the living room and hear excited squeals, you look up. There is big sister excitedly telling you how she made her sister laugh. You can't help but give up on cleaning to just watch them interact. After 10 minutes of baby screaming in the car she finally falls asleep. A few minutes later, you notice sister is asleep too. When you arrive at your destination you go to get baby and see that they fell asleep holding hands. This would warm even the most exhausted heart.
I am sure anyone out there who has a sibling remembers fighting with them. I think it would be the very rare person who doesn't remember good times too. I remember my sister and I making up our own languages. I remember making up games together in the car on long trips. I remember riding our bikes together to the library, park, and school (back when it was actually safe to do that).
It isn't just sibling pairs that create bonds. It isn't just the siblings closest in age that have bonds. The more kids you have the more interesting the bonds seem to be. In our house they all seem to have a sibling they play more with. Sometimes this changes, sometimes it is a temporary change, sometimes not. Smaller siblings, as you would suspect, always seem to look up to their next older one. There are the more atypical bonds though. These are the bonds you didn't see happening but they somehow grew strong.
A2 is #5. #1 has always been helpful. # 1 has always loved to hold the babies. She was like that even when #2 was born, when she was only 3. When #2 was a baby she hated to hear her cry and always tried to fix it. Even when #2 was a preschooler she still would always give in just so she wouldn't cry. Somehow though A2 took the holding and cuddling to heart. E14 would carry her around even when I wanted her to get some exercise through the zoo. A2 would just look up at E14 and she would carry her instead of her having to ride in the grocery cart. Now A2 calls her "Mine". Usually a toddler wants mommy. A2 sometimes only wants E14. The other day she stood at the bottom of the stairs just crying for her. She always climbs up on her lap when she's sitting on the sofa.
#2 has Autism. She can sometimes be a pain in the behind. She likes to antagonize and annoy people at times. As you can imagine this results in a lot of fights. She is very good with babies so the fighting usually is aimed at #1 or #3. At times #3 is near tortured by B11. Yet S6 already, at barely school age, is very protective of B11. She will even risk getting in trouble for lying to allow B11 to get away with hitting her.
J4 is #4. When I was pregnant with #5 my sister had her 1st. J4 seemed to have no interest in babies at all. We even tried introducing him to babies. We would let him hold his new cousin. He would sit there stiffly like he was afraid of the baby. When #5 came he got over that. He became a great big brother. When #6 came though he became attached. He tells everyone he taught her to crawl. Her first word was "bubba". He is certain he's her favorite. She loves to shower him with kisses. He doesn't let anyone else give him kisses without wiping them off. He even laughs and let's her pull his hair.
Of course these relationships could change. But Pope John Paul II said "it is certainly less serious to deny children certain comforts or material advantages than to deprive them of the presence of brothers and sisters who could help them to grow in humanity and to realise the beauty of life in all its ages and in all its variety". Their siblings will always be there for them, long after my husband and I have passed. As long as they continue to learn through the dynamics of their relationships, siblings will be an advantage to them. As long as they continue to appreciate and respect each other I'm happy. Even when they sound like they're going to kill each other, that's ok, my hubby decided that sitting together on the sofa holding hands is a good logical punishment for sibling fighting.