Quote Originally Posted by Myrdin View Post
Do we know how much exp is required for her to have in order to get the special rewerd ?
I farmed her up to 211K. Was considering 250K but I think over 200K should be more then enough.
It seems like you just need to raise her level all the way only. No need to clear entire gacha pool nor farm more exp unless you want blue macarons to change Naae's fashion sense.

Taken from wikia.
During the 2nd half of the event, a small indicator appears above your number of Sunny Macaroons which shows how many growth levels are needed for the Sapling to give you a garden object. This object will match the Sapling's highest typing when the event ends. The object is handed out after the event ends. Be aware that you can't obtain the object if you fully raise the Sapling after the event has ended.