I think...Athina is the woman between Charlotte and this man (i don't know who he is or i don't recognise him):
http://www4.pictures.zimbio.com/bg/...er+sMF5rwdOvQZl.jpg?70293EM_CASIRAGHI_B-GR_15
zeta.belle, i think this Andrea swimming: (you can see Pierre jumping into the water and Andrea swimming)
http://www1.pictures.zimbio.com/bg/...er+6KKC2IlcG0Ul.jpg?70293EM_CASIRAGHI_B-GR_21
That does look like Andrea in the water, with Pierre jumping in. I am not sure about the other pic where you say Athina may have joined them - are she and Charlotte really close enough to holiday together? If so, that's new - I know their families go back many years, but you really never see Charlotte and Athina together outside of equestrian related activities.