Hi,
First of all, best of luck to you. I was in a similar situation, although an older step-child, and not from India. One thing of importance to understand and to investigate more. When you sponsor your wife (to-be) you both will want her child to be included as a dependent and come to Canada also. Right? The Canadian immigration rules however require, at least for some countries, that for a minor child (under 18 years old) to immigrate to Canada, the permission of both parents must be given. That's right, both. For China the permission is required in the form IMM 5604.
You need to become familiar with the country-specific requirements for India on the CIC website. I had a quick look and did not see the IMM 5604 form referenced for India. However, Canada applies it's own strict rules on parental rights to it's immigration policy, so I would be surprised if something similar is not required for India dependents under 18 years old.
On the IMM 5604 form you must be able to get the signature of the birth father on the form to state he has no objections to the child immigrating, understands he may be permanently separated from his child and if trying to immigrate himself, must comply with all requirements of the Immigration and Refugee Protection Act.
Possible exceptions:
- the birth father is deceased
- the birth father's whereabouts are not known and he cannot be located (assuming an extensive search)
- IF (and I am not sure if this is an exception or not) your wife (to-be) is the only legal guardian of the child. This would need to proven of course by court documents. However, I am not sure this will work for applications from India or not, particularly if the child was a result of a previous marriage or conjugal relationship.
When you say your gf is a single mom - what does that mean regarding her past relationship with the father (divorced, separated, child-out-of-wedlock ?)
Again, you may be lucky and may not need to get this type of form IMM 5604 signed. However, you need to become fully informed on the CIC requirements for India. I suggest reading the CIC website pages specific to Indian spousal/family immigration. If the requirements are not clear to you by then, then call the CIC contact phone line and talk to an information agent directly (you need to be in Canada to do this).
Best of luck, there is a lot for you to work out and a long road ahead.
Love will prevail.