Can I wish last 4 to get it or not
It is written "First 4" so imo free reward for first 4 balloons will be available only 4 times.
But if you will buy gems as it is written it will unlock other days also 5 - 7 day wish.
I think there are two parts to the event.
- The balloons and the free rewards which must be claimed for 7 days to receive the first 4 "wishes".
- The draw for a select few grand prizes (5 winners per day) that is only available for f2p for the first 4 days. On the remaining 3 days the grand prize is only available to those who have made a $10 purchase.
I believe the balloons and their prizes will continue for 7 days and that is what you need to claim daily to get the first 4 wish prizes.