A lot of people view ordinary feminine characters as weak, just because they don’t have any other “special” skills. Things that are naturally attributed to women do not automatically make a character weak. What makes a character weak is bad writing.
Sometimes when we talk about strong female characters we are talking about warrior women-type characters. We talk about Katniss Everdeen who can shoot arrows at a great distance and survived The Hunger Games. Although some people think that in the third film she is a weak character because she suffers from severe trauma from participating in two hunger games. That is absolute nonsense. There are female characters that are physically strong and can also be strong characters. But, not all physically strong female characters are strong characters. If a female character is physically strong but it is badly written, we’re looking at a weak female character. It is not the character themselves, the person who is weak or strong, it is the characterization of that person.
There is this idea that the main character is somehow the good protagonist because they are not interested in trivial matters that most girls are interested in. And so, we tear down girls who like girly things, like somehow they are the worst thing in the world. And guess what? This is all related to the patriarchy and it’s related to gender norms and the gender binary. The idea that everything that is attributed to women is somehow weak and lesser is because everything that is attributed to men is meant to be better and more positive. So for many people, when they hear about having to make a character who is strong, they tend to think about placing attributes of maleness onto those female characters. So that character will be good at fighting, or she’ll be physically strong.
The idea that a character is interested in motherhood, or that she is a very innocent character who likes cute things, or that she is a woman who is very sexually assured is somehow terrible, is really misplaced. Characters can inhabit an entirely feminine realm. They can have no attributes which link them to the masculine at all. Nothing to do with their appearance, nothing to do with their physical strength, nothing to do with attitudes towards life. They can be the girliest girls in the entire world and they can still be strong characters. Because they are going to be written well. They are going to have agency, they are going to have interesting things to say, they are going to make interesting decisions, they are going to be at the heart of the action. All of these things are attributes that might make a character well written.
It is fine to not like a character because of the way they were written. But to call a character weak just because they have the attributes that women are stereotypically meant to have… that’s just sexist.