How to protect myself from my wife before shes granted a green card?

What can I do at the local notary in Peru before my Peruvian wife/baby`s mother is granted a green card to immigrate to Canada, in order to protect myself? I�m Canadian and our marriage isn�t going too well so a divorce is imminent. However I want them to obtain safe haven in Canada before divorce and part ways. We were married at the municipality in Lima, Peru last year. If we are to divorce do we have to go back to Peru to do this? How can I do this minimizing being hurt? The question is what can I do before going to Canada at the notary in Peru, in cooperation with her, to prevent her from exploiting me, using Canadian laws against me and getting child support from me? I don`t have much money, I only receive montly provincial disability support. My wife now is willing to sign or do anything to make me feel reured. Once she is a legal citizen with rights in Canada she may be less cooperative, and change sides and try to harm... I want to believe not but who knows! We already did a seperation of money/goods before getting married. But I don`t want to pay child support. She is an educated professional. I am not. She can get any job and make big money. I can�t. Can you folks tell me what I need to do exactly while I still have the chance. Thanx!!