Westeros is not realistic, grittily or otherwise. To begin with, medieval Europeans understood that marriages were only valid if they were consensual, and so they went to substantial lengths to gain that consent or its appearance. In Westeros, nonconsensual marriages are a shrug.

Westeros also features substantially greater social acceptance of pedophilia than existed in medieval Europe- marrying eleven-year-olds and expecting them to have sex with adults was outside the bounds of acceptable behavior there, but is just slightly uncouth in Westeros.

Women fighting is seen as completely incomprehensible to Westerosi, to the point where Brienne of Tarth is a freak and the Mormonts are weird. For medieval Europeans, it was unusual but they had various historical models to contextualize it.

Women having a profession is seen as similarly unusual. Again, in medieval Europe, the small class of professionals generally included both men and women, and widows would continue to run the shop if their husband died.

Medieval Europe was very, very sexist. You can read Christine de Pisan's The Book of the City of Ladies to get a good sense of that, but most importantly, people were pushing back against it, and it existed in a discursive form where Westeros is fundamentally a monolith.