Some ID help needed please

Afternoon all, hoping for some help please solve a family discussion - is this chap/ess a willow warbler ?? Not seen one before but that said we're all newbies to this, not one I've taken but my son and his girlfriend visited there with her family yesterday and it was his girlfriend who took the snap.

Interestingly they also spotted what looked like a very large terrapin or possibly a turtle - is this a usual spot there ??

They also managed to spot clearly from one of the walkways what looks like possibly a moorhen nest complete with eggs (eager to point out that apart from pointing the lens through the reeds they didnt disturb the area or nest at all hence the poor quality of pic!)

Thanks in advance

Nic