control thing to my sister and a little of my sister's devil may care to your sister.
Is your sister older? Some of the problems I have with my sister and brother is they are 14 and 13 years older than me and still occasionally think of me as a kid. Sometimes it annoys me. Sometimes, they insist on paying for my meal and I'm fine with it <g>.
A bit of an update: so, my "communication is important!" sister...could you tell our brother that? I texted him HOURS ago to tell him of my change of plans and apologize, even though I don't really think I have anything to apologize for except maybe not letting him know stuff sooner, and I've yet to hear back from him. This is why I don't like planning via text, or even e-mail. I prefer sit down conversations when possible or phone calls when not.