Playing with my fiancee on monoserver

If you both contact Support and ask they may be able to sort it so you can both play but both accounts have to be verified and you may need to provide proof of ID (if you send all this information when you first contact them it will make it quicker and easier for them to assist you)

Below is what the Support page says on the matter, specifically the DOFUS & Temporis bit:
A single player may only log in with a single account at a time on each server.
We verify certain information, such as IP address, email address, or phone number, to apply this limitation.The following restrictions are related to the main restriction:

• The account must be certified (i.e. linked to the account creator's true identity).
[*]The account must be linked to an up-to-date phone number  .
If you don't have a cell phone number, you won't be able to access this particular server. If you're not receiving our text messages, or text messaging isn't available for your country or region, please submit a Support ticket. 
• Only one connection per IP is possible.

DOFUS & Temporis Specific :

• We're aware that these IP restrictions may block players sharing the same Internet connection (family members, housemates, etc.) who wish to play together regularly. For this reason, we allow a second login from the same IP, but the other criteria must still be met.
• 4G connections are allowed for couples, families, and housemates. Please note: This does NOT mean that multi-accounting is allowed.

https://support.ankama.com/hc/en-us/articles/115013728988--DOFUS-How-does-single-account-mode-work-

Thank you both for the response,disappointing news but rules are rules !