I mean, yeah. It’s easier for kids to recognize if they look the same but have different hair and eye color and styles.
As a wannabe animator I can say for certainty that hours and days and weeks and months of hard work we’re put into...
plus, Anna, Elsa and their mother are supposed to look similar like hello they are relatives.
The mom doesn’t even look *older*. She just looks paler and a little sick. Seriously, wrinkles - women get them too!