1. You can take various documents documenting co-mingling of assets such as financial documents, insurance information where you have each other listed as beneficiaries, mail addressed to the other party not residing at wherever it is you both regard as your home as proof you both reside together, etc.
2. Not a bad idea to do so.
Hi mom:
My wife also receives IL, and the interview date is next month, three weeks after me. The notice mentions that I must go with her.
I'm studying the interview tips now. Thank you for the help!