You could consider one of the following
Let her do Leaving Cert this year in her current school, with a view to repeating at a Grind School.
More expensive. Send her to a Grind School now, but to 5th year repeat. The advantage of this is that she and you would have time to reset, get exemptions/help sorted re dyslexia. Some subjects are taught in two year cycles so she would have 2 years to study poetry/plays etc rather than cram them into a one year repeat. Schools which are full for 6th year might not actually be full for 5th year.
Grind schools often have "high" entry requirements, based on Junior Cycle or 5th Year results. They are looking for above average students. In DDs school, many students who excelled at JC opted to transfer to Grind School for 5th and 6th year, none of them did as well at LC as the highest achieving students who remained at the state school. However, they may have achieved their dream course.
Don't automatically knock the Foundation level option. It's possible to gain entry to Level 6/7 courses. What does your daughter want to do in the long term? If it's something that requires very high points, is she prepared to knuckle down and put in the hard graft required? But academia is not for everyone and Foundation offers a different approach.
Very few young people are "self-taught". This might well be possible for a reading subject like history but once it gets slightly technical like geography, physics, chemistry, maths you absolutely cannot do it yourself unless you are genius level. Throw dyslexia into the mix and you have to deal with a whole different ballpark. You've had your eye off the ball for a while now with the homework situation and you may need to adjust your own expectations. This is not a criticism, just acknowledging that LC year is not a great time to be expecting great changes and improvements. Perhaps arrange a meeting with the school guidance counsellor or splash out on a private session for some professional advice. Play to her strengths, establish where they lie first. How did TY work out for her, what did she enjoy best in relation to work experience, modules etc?