My wife received the same letter yesterday asking for more proof of relationship/cohabitation.
When we sent in our application (early March) she had only been in Canada for about a week, so the only document she had with our common address on it was her private health insurance.
We had sent a letter from my father explaining that we were staying with my parents, so our names are not going to be on any bills, etc. Not much has changed since then other than we have more traveler's insurance docs spanning Feb-Dec and an additional mail receipt or two.
When we sent in our application (early March) she had only been in Canada for about a week, so the only document she had with our common address on it was her private health insurance.
We had sent a letter from my father explaining that we were staying with my parents, so our names are not going to be on any bills, etc. Not much has changed since then other than we have more traveler's insurance docs spanning Feb-Dec and an additional mail receipt or two.