If you want her to remain in the country for additional months, apply for a visitor record or extend her stay. Visitor visa is generally for entering the country.
Further reading:
https://www.canada.ca/en/immigration-refugees-citizenship/services/visit-canada/extend-stay.html
You need to explain your plan to sever your ties with Costa Rica (get rid of everything you have). upon the certainty that your wife's application will be approved. For example, arranging relocation companies to ship things in Costa Rica to Canada, etc.
But the child can move to Canada first. Have the uncle as her guardian. Once the child is in Canada and enrolled in school, this would be a strong proof that OP will move to Canada.
According to this webpage, the sponsor have to pay $1205 or more to sponsor a spouse or partner; sponsor child from $170:
https://www.canada.ca/en/immigration-refugees-citizenship/services/immigrate-canada/family-sponsorship/spouse-partner-children.html
For more info...
According to "https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/temporary-residents/visitors/three-types-visas.html", it says:
The multiple-entry visa
can still be valid if affixed in a full or complete passport or travel...
With that income, perhaps they can hire someone to take care of the cooking, cleaning, laundry, shopping, anything related to the baby (instead of the husband doing so).
If you are planning to sponsor her under the family class category, please post it here:
https://www.canadavisa.com/canada-immigration-discussion-board/forums/family-class-sponsorship.5/
So you essentially showed flags that your father didn't do well in his business, when you provided a letter of financial support along with employment letter, pay stubs, and bank balance for the last three months.. Your notarized invitation letter holds no value. I don't see any suspicious...