can i have some advice please?

[HowToProceed]

hey guys can i have some advice please? firstly, this is about my youngest child, who we believe to be NT. bit of background first. sorry, it will be long.

i have 4 children, a son aged 16 who is nt as far as we know, a son 14 who has high functioning autism, a daughter 10 who has adhd with the possibility of pda (will be explored later this year), and a daughter 9 who is nt as far as we know. the girls father has a diagnosis of adhd, but i suspect this is just the tip of the iceberg. we have not been together for 8 years.

my youngest is having troubles at school, i believe a severe personality clash with her year 5 teacher. she had no such issues with her last teacher. she is very unhappy, and today got banned from doing swimming any more, we believe from a row with the teacher. she is very strong willed, and unable to keep her mouth shut when she feels she is being treated unfairly. she was removed from the swimming pool early today as she takes a while to get dressed, and she turned the heating on in the changing rooms as it was freezing. she has been given a detention for this, and banned from swimming for arguing with the teacher and refusing to get dressed because she feels that she was unfairly treated. i am not sure what to do about this firstly, but also, school want her assessed by the ed psych, and i am unsure what i feel about it. my older daughter has been assessed and statemented, and i feel the youngest is nothing like her, although may have learnt some behaviours from her older sister as they are very close (less than a year apart) and share a bedroom.

i dont think she has any learning issues, she is a very bright little girl, and could do well easily, but she is lazy, and doesnt like doing her work. she will make excuses, or try to be helpful to avoid doing work. she did have these issues last year with a different teacher, but to a much lesser extent and i feel that this has now turned into a battle of wills, with the teacher determined that my daughter will do as she says, and my daughter determined that she will not. any advice on how to proceed would be very gratefully received as i am getting to my wits end. thanks