The plan was that XD, the queen had a bug in the count event so she let you pass. In the current version I already fixed. The slime quest is from Mei at the magic shop, in theory if you do all the six mini quest and you are left only with the slime quest to be done, when you enter the city Helen will say "I think I should speak to Mei at the shop" as a tip to send you there.
For more info you can send me a private message if you need on Itch.