Re: sibling rivalry
I think it's a good idea to keep an eye on your DDs' relationship. My younger sister and I were brushed off by my parents, with the result that I hated her throughout a lot of our childhood, and we still don't get along. I think we both were damaged by family dynamics. We even tried therapy.... All of which is to say a stitch in time saves nine. Be well aware of how they each might be feeling, read up, and be conscious of what you and your sister are modeling for them. This is what I'm trying to do for my daughters, anyway.