Some people view the concept of disability as a light switch, you're either functional or you're not. She's clearly very functional. She may need help in some areas but that's not our business and she seems able to live an interesting life. Having Downs doesn't mean she has special needs, but she is divergent. Some live very normal lives, they just look different and have the chromosome issue and the immune and other things that go with it. It's not the instant super-support need it once was.
100 years ago needing glasses was a hit and miss of disability and functionality. Now, people barely acknowledge it. Not making passes at girls who wear glasses was something that went into the early 2000s, holes in the gene pool.
It is crazy how people want to insist that so many people need to be treated as children.