I missed the first bit of this so have watched it on catch up.
I think the single biggest issue is the extent of the baby's injuries.
The fact that the mother is refusing to admit that her partner could have been responsible shows a startling amount of denial.
Babies do not acquire severe cerebral palsy without a significant brain injury and brain injuries do not 'just happen'
That being the case how the hell does she think her baby became so catastrophically brain injured?
THose text messages suggest she knows he hurt the baby. 'Changes need to be made' implies that he had already harmed or come close to harming her.
There is something odd about her. The very fact she is allowing herself to be filmed and identified shows a lack of insight. I have worked out what part of London she is living in (I am pretty sure) and she has a very distinctive look.