Been in a relationship about 5 years 4 of those years living at her families house she could not handel living there no more I said I would buy a house if she got a job she has one kid one month in the house she quit her job and now she is threatening to take me to court need some answers and we are only commonlaw in ontario thanks

Since you are not married and her name is not on the mortgage then she has no rights to the house. Basically she doesn't have much, if any more rights, than a couple shacking up.
If people could live together and automatically have as much rights as if they were married the courts would be in a bigger mess than they are.
If the kid is yours she can get you for support on that angle.
Are you just living together and calling it common law or did you sign anything?

Here is a Canadian site explaining common law
Differences between marriage and common law separations in Canada (http://www.common-law-separation-canada.com/differences.htm)

Most common-law couples don't know their rights (http://www.canada.com/montrealgazette/news/business/story.html?id=a507ac9f-4000-4031-b74d-7c2a1e385164)