No I am not making things up. His morther married a English man and moved to England she most likely applied for and was granted UK Citizenship. If so upon her arrival in Canada she as a citizen of the UK could have gotten Canadian citizenship in just one year. She was on the voting rolls, which requires citizenship, so she likely was in fact a Canadian citizen just like her husband.
Not so.
From Dallas Morning News, July 6, 2016
Wilson confirmed one fact critical to Cruz’s presidential campaign, that Cruz’s mother never became a British subject while she was working in London. Despite his many years in Britain, Wilson said he too never became a citizen of the United Kingdom.