DS1 (age 13) has something similar to deal with, although not exactly the same. DS1 has the high IQ, high memory (all types) and dysgraphia.
(Dysgraphia is the writing part of dyslexia.)
I am sure you've started googling already, but in case you haven't found it look for twice exceptional (also called dual or multiple exceptionalities, dme, 2e). The profile of average performance is common because the intelligence masks the SEN and the SEN masks the intelligence.
The bad news is that its really hard to get any help. Schools are not measured in a way that slices and dices this way and so you end up relying on the good nature of the teacher to help. If the SEN wasn't there, your DD would be scraping up against the glass ceiling of maximum learning. If the ability wasn't there, she'd qualify for the active interest of the SENCO and various interventions aimed at getting her into the normal range.
My own experience is that the child takes it really badly. They know what they want to do, they can self analyse, and they hate the SEN with a passion. I think it must be like being an olympic athelete whose leg is in traction. Helping DS deal with this mental hurdle has been the biggest challenge for me as a parent.
Practically, from an education point of view, all you can do is make sure the school (SENCO) and individual teachers recognise the diagnosis and will make whatever accomodations the ed psych has recommended. TBH I don't expect that you'll always get the sort of support you are currently experiencing from the school as it does vary according to the individual who is the teacher and their attitude to whether average is good enough.
DS1 is actually doing very well at school. He's top set in every academic subject and for some, he's top of the top set. I don't know what the future holds. I hope DS will be able to find workarounds so that he can still excel despite his disability.
My advice to you would be to research it all as best you can. Speak to everyone you can to see what workarounds may help your DD and try them all. Then just keep going, taking each year as it comes. But do watch out for the mental impact as she grows up and starts to really mind being different.