You could check out 'The Powerpuff Girls'. It's all about these three super-powered girls fighting crime. Another option is 'Tangled', where Rapunzel is the main girl. These cartoons are widely enjoyed by audiences of all ages.
One of the well-known ones is 'Dora the Explorer'. The titular character Dora is a girl and is loved by many kids. Also, 'My Little Pony' has various pony girls that are quite charming.
There are many! One example is 'Sailor Moon'. It has a beloved girl protagonist and is widely popular.
One popular cartoon with girl scientists is 'The Magic School Bus.' The main character, Ms. Frizzle, is a science teacher who takes her students on wild adventures to learn about science.
One popular one is 'Miraculous Ladybug' where Ladybug sometimes has to deal with medical situations. It's not strictly about being a doctor, but has elements of it. Also, 'The Magic School Bus' has episodes where they learn about health and medicine, kind of related to girl doctors.
One popular one is 'Love Live!' It showcases a group of girls striving to become idols. The animation and music are both great.
One popular one is 'Doc McStuffins'. It showcases a smart and kind black girl as the main character.
One such cartoon is 'Twins' World'. Here, the girl twins face various challenges in a fantasy land. The animation is colorful and the storylines are engaging.
There's 'Brave', where the main character is a girl and there are magical animals. 'Tangled' too has a girl and cute animal sidekicks. 'The Lion King' might also count, as it has animal characters and sometimes involves human girls in the story.
One popular one is 'Doc McStuffins'. It shows a smart and kind black girl who helps fix toys.
One such cartoon is 'Steven Universe', where Ruby is a notable redhead character.
There's 'Mickey Mouse Clubhouse' which sometimes features little girl mouse characters. It's colorful and fun for kids. Also, 'The Secret World of Benjamin Bear' has some charming little girl mouse moments.