Here is the official version (Health Insurance Act - R.R.O. 1990, Reg. 552):
4) The three-month waiting period referred to in subsection (3) does not apply to the following persons who are residents and who apply to become insured persons:
1. A child under the age of 16 who is adopted by an insured person.
2. A newborn born in Ontario to an insured person.
3. A person who satisfies the General Manager that he or she has been resident in Ontario for at least three months at the time of his or her application to become an insured person.
Follow the following link to download a PDF document and then print it out as a proof: