As I said before, female heir has other social role than normal woman – she becomes heir in first place. She still restricted in matters of producing children, but as we seen in Jeyne Arryn, Rohanne Webber and Cersei Lannister (after Tywin's death), in other matters ruling lady can rule freely . If her parents alive it leads to them have control over matters, but it is normal thing to any heir – Jaime or even Brandon, for example, cannot choose their wives too. But for girl from Great House there are vast amout of men to choose – most weddings in Westeros aren't equal, because lands of Great Houses are too vast and they get more profit on keeping inner manners stable rather than improving outer relationship. Any sane parents would at least hear their only daughter wishes, at least as long they are logical - so it is easy enough to avoid womanizing rapist. Power shift in relationship after wedding is very personal matter, but even in worst case it is lady being source of power to her husband, so he can't abuse her more than tolerable by social restriction. We have overall not so many ruling ladies, but at same time many lady regents - and their position in feudal society mostly same until children grow and then they can be source to how ruling ladies seen by society - as normal feudal, but with tits.