Medieval people generally observed the notion of gender division — that is, men associated mostly with men, while women associated mostly with women. You might say that medieval society was a divided one, split along gender lines. The reason we know so much more about the roles of men, and the reason that men appear to have dominated medieval history, is because history was — largely — written by men. Naturally, they spoke of what they knew best, which was their own, masculine, portion of society.
The situation was worse for women than it was for men. The medieval diet lacked iron, which women need even in greater amounts than men. Many women were frail, therefore, during their childbearing years, and death while giving birth was commonplace. So, while women were generally spared injuries from warfare, they died — on average — much earlier than men. Those who survived their childbearing years, however, generally lived for a long time — longer than men of the same age.
This naturally gave rise to the notion that women were — by nature — frail, & required the constant protection & help of men. The harsher chores of any household, such as plowing fields & tending crops, were reserved for men, and women performed work which required less exertion, such as cooking, weaving, etc. (Of course, don't be fooled into thinking this was "easy" work — it was very physical, just not quite as physical as the work reserved for men.)
Even after this, however, boys (as well as girls, of course) tended to maintain close relationships with their mothers. Motherhood was something to be honored, almost a mystical ideal, and men were usually expected to show their mothers deference & respect. Medieval people had a particular reverence for motherhood.
This "veneration" of motherhood had religious implications, as well, & indeed may have been inspired by their religion. Mary the mother of God was idolized extensively, — shrines & hospitals were set up in her name, she was prayed to, and so on. Motherhood was considered something very sacred & precious. A mother was always to be respected, not only by her own children, but by everyone. The mothers of kings held courts of their own & often had their own influential factions.
Another strong woman of the Middle Ages was Melisende, Queen of Jerusalem. She was the sole heir of the crown of Jerusalem, & her father & other Crusaders arranged for her to marry Fulk V, Count of Anjou, a famous military leader, intending for him to be the next King & continue the war against the Saracens surrounding them. Fulk did indeed rule Jerusalem, all but ignoring Melisende. But they had a falling-out (over a rumor of her infidelity) and their partisans came to blows over it. Her followers prevailed & thereafter Fulk had to treat her as a co-ruler. After Fulk's death she ruled as regent for her young son Baldwin, & stayed on as ruler even after he had come of age. Find out more about Melisende of Jerusalem.
Some of the most revered holy figures during the Middle Ages were women, such as St. Catherine di Siena. Additionally, some of the women mentioned in the Bible, in the Old Testament (Ruth & Rachel, for example), & in the New Testament (such as Mary Mother of God, Elizabeth, & Mary Magdelen) were considered models of piety, each in her own way.
The Church operated a number of hospitals and infirmaries. While some of these were run by the Benedictines and other orders (later, by the Knights Hospitalers), most were run by nuns. In fact, the better-known physicians & healers of the Middle Ages were women. Medieval people believed that women had a better capacity for care-taking. The same was true of poor-houses, which were also primarily run by nuns.