My mother had a much harder time with my sister than she'd had with her two much older brothers (there's a 9 1/2 year gap between me and my sister). It wasn't my mother's age, or even her MS. My sister was much more rebellious than either of her older brothers, and had less of the caution genes which run in the family. My sister did a lot of stuff (like taking up smoking, and taking the car out for a drive when she was 14) that her older brothers never would have done. But she became a fine adult, and was responsible during covid for getting Fairfax County, VA vaccinated.