What about in your work permit extension application? Did you say you were single or common law? What about her? Has she filed any immigration applications since Aug 2023 and what did she list as her status in those applications?
Photographs and chats aren't regarded as proof of common law status.
You want to provide evidence such as joint leases, joint bank accounts, etc. It will work against you that both of you failed to declare your common law status in your IRCC applications and tax returns.