how did you kill izzy
i tried attacking her cities but her units always killed mine; even if they wer the same unit
you need catapults. You can use the bombard function of the catapults to reduce the defenses, and when these are at 0%, attack with several catapults wich will probably die, but cause collateral damage to about 5 units each. You'll see that the odds suddenly rise after a few losses.
This kind of blocked off situation really calls for an attack, and catapults before Isabella gets longbows is probably your last chance. Going for horse archers would have been better, but it should have been done earlier.
You have about 20 spare military units already, You could divide them into 2 armies, and add 6 catapults to each. To get enough catapults, chop forests. It seems you haven't chopped a single forest yet. You have 8 workers, wich is really too much, if you don't chop forestst, but they come in handy now.
You should also use the slavery civic, as soon as you have construction, start producing a catapult in thessalonica, constantinople and adrianople, wait for one turn and then press the button with the orange arrow on the bottom right that should say
"Hurry catapult, costs 2 population", the catapult comes out next turn. I would do this several times, because the citizens that disappear in these cities only work unimproved forests and won't really be missed.
If you go for an early attack with catapults or horse archers, do not settle any
low value cities. That island city and the settler you are building now won't help you produce catapults faster.
Build a lighthouse before you build the moai statues. Water tiles will still be useless without the extra food from a lighthouse.