11 year old daughter

Maybe start by teaching and helping her practicing doing her own braids / plaits on a weekend morning when there is less time pressure and stress of "got to get to school".  (The idea being that it should not feel like a "punishment or chore" associated as part of getting ready for school).

She might find it easier to practise with strands of string tied to something first.  Then maybe on a long-haired doll.  Next on her own wet hair.  Finally graduating onto doing her own hair. 

Maybe explain that if she is nervous about a particular school day e.g. school play or school photo day - you are still hoping she will let you be involved if she would like that and would love it if she could tell you by the night before that day.

If the school uniform rules permit decorated pony tail bands / ribbons  perhaps going shopping together (just Mother and Daughter) as part of the ritual celebrating her new skill would be nice for both of you.

If she is an Autistic young person really bothered by touch and textures - you can get pony tail bands with nothing on the covered elastic at all - not even the potentially scratchy little metal elastic end-joining clip.

Maybe try to acknowledge her efforts now and again - perhaps at the end of a school weak (not trying to make a new daily ritual) - "I noticed you did your own plaits really well on lots of days this week".

Depending on her preferences, and the school rules, you could try sowing the seed of an idea that one day she might like a different hair style.  (Some Autistic young women can oscillate between liking either long enough hair to braid / plait / tie back in a ponytail or bunches versus a really short hairstyle).

Depending on her hair texture, she might benefit from a wider-toothed plastic detangling comb rather than a brush.  Important to explain the basics of starting to comb / brush from the bottom of the hair strands and then work your way up towards your head - to detangle the hair before attempting to plait / braid the hair.

If you can find a product with which she is happy (fragrance etc.); a leave-in conditioner can help to tame the hair ready for someone with her hand size to work with the hair more easily.

Maybe start by teaching and helping her practicing doing her own braids / plaits on a weekend morning when there is less time pressure and stress of "got to get to school".  (The idea being that it should not feel like a "punishment or chore" associated as part of getting ready for school).

She might find it easier to practise with strands of string tied to something first.  Then maybe on a long-haired doll.  Next on her own wet hair.  Finally graduating onto doing her own hair. 

Maybe explain that if she is nervous about a particular school day e.g. school play or school photo day - you are still hoping she will let you be involved if she would like that and would love it if she could tell you by the night before that day.

If the school uniform rules permit decorated pony tail bands / ribbons  perhaps going shopping together (just Mother and Daughter) as part of the ritual celebrating her new skill would be nice for both of you.

If she is an Autistic young person really bothered by touch and textures - you can get pony tail bands with nothing on the covered elastic at all - not even the potentially scratchy little metal elastic end-joining clip.

Maybe try to acknowledge her efforts now and again - perhaps at the end of a school weak (not trying to make a new daily ritual) - "I noticed you did your own plaits really well on lots of days this week".

Depending on her preferences, and the school rules, you could try sowing the seed of an idea that one day she might like a different hair style.  (Some Autistic young women can oscillate between liking either long enough hair to braid / plait / tie back in a ponytail or bunches versus a really short hairstyle).

Depending on her hair texture, she might benefit from a wider-toothed plastic detangling comb rather than a brush.  Important to explain the basics of starting to comb / brush from the bottom of the hair strands and then work your way up towards your head - to detangle the hair before attempting to plait / braid the hair.

If you can find a product with which she is happy (fragrance etc.); a leave-in conditioner can help to tame the hair ready for someone with her hand size to work with the hair more easily.