I've never been a fan of Diane Abbott. I don't believe she would have been shadow Home Secretary had there been a different labour leader, with the whole parliamentary party to choose from.
I am however, concerned that there isss a health problem. The sky tv interview last night was so bad, I could only watch a bit of it (I'm also away with only intermittent iPad access to news). Her speech seemed slightly slurred and even slower than usual. She looked unwell and obviously struggled to deal with a fairly combative interview. She should be on top of her brief and she isn't, As shadow Home Secretary in election week she should have been prepared for he questions. An experienced politician ought to be able to respond, to have full confidence they know their department and can set out criticicisms of the current government and her own plans to operate more effective counter terrorism.
It was embarrassing and uncomfortable to watch her waffle, totally out of her depth. I find it impossible not to conclude there is a significant health problem. Any employer would surely recognise something is wrong and she needs to take time out.