Hi, I've had 2 ds with chronic health problems affecting school attendance. Whilst agreeing with what Drinks has said, the amount of interest in the issue can vary wildly not just between different education authorities but also from school to school in the same area and even at the same school at different times.
I don't know what your dd's health problems are, but I think some schools find it easier to offer help if they have some understanding of the condition. Both my ds's "look normal" and have conditions that school staff didn't really understand, or in some cases believe.
My oldest had around 40% attendance from Yr 6 to Yr 9 and got on a more even keel in Yr 10. The primary school was fine and the secondary school was mainly very good (a few dodgy blips still) and he was seen as having special needs even though he had no learning disabilities (apart from being constantly ill!). His fantastic form teacher (vertical grouping so stayed with the same one), various heads of year and the SENCO were involved in regular meetings with me and him to keep things on track and teachers sent home work regularly. He also had access to the local authority's e-learning lessons. He managed to complete all but one of his GCSE courses and came away with As and Bs so very happy.
Fast forward 6 years to the youngest ds and it all changed. The primary school, in special measures at that stage, could not disguise their suspicion of us as parents although an eventual diagnosis at Great Ormond Street calmed this down. He attended the same secondary as his bro (around 30% attendance dropping to 22% when he left in Yr 9) but what a difference. Within 2 months of starting in Yr 7 we were being asked if we'd like to home educate him (err no!). We weren't allowed to even see or communicate with the SENCO. We were told ds didn't have special needs as he didn't have a learning disability. All meetings started with a discussion of his attendance figures and how bad they were until we complained this was pointless - we knew where he was, at home ill with us. Very little work was sent home. The local authority e-learning lessons were set up so school seemed to take this as "job done, we don't need to be involved" even though this is clearly not what the law says. Phone calls and letters of complaint to the HT were ignored until we threatened further action. A letter to the governor in charge of special needs was never passed on. Ds had mobility problems and couldn't access all the classrooms but was regularly left in another room with no work. When, in the middle of all this, my dh became seriously ill we withdrew ds from this school (rated as "good" by OFSTED) and started home ed using an online school.
After his dad's death, ds returned to mainstream local state education towards the end of yr 10. I had to appeal to get him into the school that he and I wanted (the "good" school offered would have been pointless - too much like his first one) and it is just so much better going into meetings not having to gear up for a fight. Unfortunately, having got his attendance up to 60%, ds has had a massive flare up and hasn't been in school since mid November. The school (also rated "good" by OFSTED) has stayed supportive and ds still has access to online learning from the local authority. He is currently taking a reduced number of GCSE courses, exams due soon.
I know the first secondary school were in breach of almost everything they were supposed to do to help my ds but there are only so many fights you can have especially when they all come at once. I wish ds could have started where he is much earlier but with his dad's illness and death I wasn't in a position to sort it all out and we all believed at that point that none of the other secondary schools would be any better. I am certainly very cynical about OFSTED judgements as the "good" schools are so different it is unbelievable.