Board Thread:Speculation House/@comment-4830106-20140806180925/@comment-7472785-20140817192344

In reference to nobility versus private owned company:

All children of the monarch are princes and princesses (and that's what Ruby called Weiss in episode 1), only the first in line of succession is crown prince/princess.

So heiress is not necessarily the sole heir, and she could be any of a number of siblings. We derive that notion only from her trailer where she calls herself loneliest of all - but that could have a number  other reasons. Being a late child with the mother dead early could well be one of them.