Siblings. Please Advise.

I'm an only child. Therefore, I haven't a clue how siblings are supposed to interact....aside from witnessing the sibling relationships of a handful of childhood friends and relatives. Very few of my friends had sisters. This means almost every sibling relationship I saw was fraught with merciless teasing just a hair's breadth away from Torquemada-like torture (Exhibit A: my close friend Jen spent a large portion of her early years having her face farted on by one of two older brothers. Exhibit B: another friend was regularly locked in the hall closet by her brother. It goes without saying she now suffers from acute claustrophobia).

Apparently sister relationships are much more complex (and complicated) than the ones between brothers or brothers and sisters. I know of some sisters who haven't spoken to one another for years. I know of others who never bothered to make close friends because they have each other. And there are myriad relationships that fall somewhere in-between.

When I was a child, I desperately longed for a sibling. I always felt like I'd missed out on something very important. And as an adult, I wonder who I will be able to share my past with when my parents have gone. A sibling isn't just a companion/arch enemy but also an important link to shared experiences and family memories, idiosyncracies, etc. This is the main reason why I swore to have no less than two children.

But being an only child isn't the lonely, selfish exile so many people make it out to be. As an only child I was able to befriend myself (something many people spend years of therapy trying to do) and happily embrace long periods of solitude. I also was given many opporunities by my parents that would never have happened had we had an extra mouth to feed (trips to Europe anyone? private school?)

I guess what I'm trying to say is there are pros and cons to both. And as an only-child parent of two little girls, I feel pulled in two directions. I feel totally unqualified to provide any guidance whatsoever to my girls with regards to the whole sibling thing. For example, M constantly roughhouses with Z when she's feeling particularly tired and cranky. Yes, I realize this is the norm for siblings. But I can't help but feel protective of poor Z who is clearly too young to defend herself. However I also don't want to discourage M from interacting with Z....nor do I want M to feel like I always take Z's side. And I feel guilty that I can't give them both the full attention I received from my parents.

Ack!

I suspect most of you had a sibling or two growing up. So I'd like to hear what you recommend in terms of dos and don'ts. What worked? What didn't? What can you now see the wisdom of in retrospect? Do tell.