I think you have misunderstood something. A child by itself will not get enough benefits to support their parents. If it did, people would just have children and nobody would bother to work.
There is however the Canada child tax benefit, see http://www.cra-arc.gc.ca/bnfts/cctb/fq_qlfyng-eng.html
To be eligible, you must meet all the following conditions:
- you must live with the child, and the child must be under the age of 18;
- you must be primarily responsible for the care and upbringing of the child;
- you must be a resident of Canada; and
- you or your spouse or common-law partner must be a Canadian citizen, a permanent resident, a protected person, or a temporary resident who has lived in Canada for the previous 18 months, and who has a valid permit in the 19th month.
Here is how they calculate it: http://www.cra-arc.gc.ca/bnfts/cctb/fq_pymnts-eng.html#q9
The base amount is $113 per month per child. Low income families could get a bit more.
As for Maternity and Parental benefits which is the name of the post, that is a completely different story and is not paid per child but per parent and you must have earned them. You can read about that here: http://www.servicecanada.gc.ca/eng/sc/ei/benefits/maternityparental.shtml
To get it, the mother must have worked at least 600 hours in the past year. She can then get Employment insurance, 55% of her gross wages up to a maximum of 468$ per week. She can get that for 15 weeks. After that, there are parental benefits available for up to 35 weeks total. The mother can take them all or share them with the father or the father can take them all as they wish.