@Scaredaboutthis I'm also in Ireland - I have a DC doing Leaving Cert too (and one doing Junior Cert - he's stressing me out more than my LC child!)
You're sounding a bit vague about where your DD is at - you say she 'passed' her mocks - do you mean she passed each of her subjects? It's obviously different in Ireland (comparing LC with A-levels) as students typically sit 7 subjects, and count 6 for CAO purposes (3rd level).
Firstly, is she aiming for third level - university / TU place? What has she on her CAO, and how many points were they last year? If so, I assume she has applied for DARE?
If she isn't planning on going to third level, has she a PLC or similar training course in mind? If so, she will not usually require very high results in her Leaving Cert, so if that's the case, she can do the best she can in her exams, and just focus on the course next year, while she works out what she wants long-term.
If she is planning to take a PLC, you can help now by checking the supports available for her dyslexia in that college, and also, where she can go from there, e.g. is there a progression route to 3rd level? If there is, most universities are very helpful regarding requirements and transition; no rush to do this now, but early next academic year, contact the individual institutions to discuss this (I work in a university).
Back to the exams, while some study can certainly help now, it's too late for massive amounts of learning. Instead I would focus on the practicalities of each exam - the LC is brutal in terms of the schedule, so plan what she needs for each day and how she can be best prepared.
For revision, her teachers will almost certainly have given her revision notes / .ppt slides / areas to focus on, and these will be in Teams / Google Classroom, whatever platform the school uses. Focus on these, not the books.
Finally, for the subjects she is aiming to do well in, get her to do a few exam questions every day until the exam. Not for every subject - it's too overwhelming with 7 - but the 3 or 4 she really wants to focus on.
Most schools are finished / finishing for 6th years but most teachers are happy to be contacted until the end of next week, so if she has course work she wants marked, she can go to them still.
All of the above is a useful plan to maximise her LC experience, but also take the stress out of it all for her, and you.
Best of luck!