Hi Ruthandsam,
This does sound very trying indeed! I work with young children as a profession and my only advice I can offer is to keep on with a particular method of discipline... I may have rwad wrong but it sounds as if you are tryin various things as punishment when really, all you need is one and make sure you follow through each and every time she misbehaves. Our method at the Playgroup I manage is... they get a warning for their bad behaviour, if they continue then they will be put in 'time out' ( which is away from the immediate situation) and given a FIRM explanation of why they are there, i.e... you are here because you didnt listen and hurt the cat, then walk away and blank the child. They MUST stay in that specific area for 1 min per every year of their age, if they get up from that spot before this time is completed... then they get taken back each and everytime with no communication whatsoever, when they complete the 'time out' then another explanation is required so as to remind them of exactly what they did and then an apology is required, if they dont apologise then another 4 mins (for your childs age) is dished out, and so on until you get the desired positive behaviour. Hope this makes sense! She may also be over tired from doing long days where she'll be required to concentrate longer on specific tasks at nursery.