Thanks for answering so soon.
I think what Steph said makes sense: she and Al have very different and busy lives; plus I think as close as brother and sister can be, they usually spend less time together than two sisters or two brothers, as they tend to enjoy free time in different ways. It's similar to the difference of a son or daughter with a mother: often mothers are very close to their sons, but they end up spending much more times with a daughter than with a son. Just my two cents...
BTW, Steph is changing a lot lately, but I don't think she'd enjoy living at the Palace,
Kisses