Hi - this is a really complex situation and even if I had everything in front of me I'd be loathe to speculate on what decision might be reached.
Generally speaking, she should try to get some advice from a family law clinic regarding her domestic situation, the absence of a sponsorship and any impending removal will see potential custody issues.
Here is the online manual link
https://overseastudent.ca/migratetocanada/IMMGuide/CICManual/ip/ip05-eng.pdf
A well laid out H&C should refer to the elements of this manual and how her application corresponds positively with Canada's policies.
The application is "alive" until it's decided so the application should always be updated with any information that's important for the decision-maker to have in front of them as they weigh the material provided.
The decision is discretionary and the Officer has nearly complete autonomy when coming to a conclusion, so it's important to be organized and point to the policies in play within the person's situation.
Earlier actions that could be viewed as a negative should be addressed, explaining perhaps the refugee claim or any other things that happened that might effect credibility. I don't know anything about the claim or her country or origin so this is a general statement regarding how encompassing the H&C considerations can be.
Having children, whether born in Canada or not, isn't decisive in itself and the younger the children then the less likely it is to be compelling that they remain in a country where they can't be more substantially integrated because they're infants or toddlers.
It is unusual that there is a marriage and no sponsorship so that's something that needs explaining.
Some people on here enjoy predicting outcomes but from what I've seen they're over their heads. Nothing replaces a competent lawyer dedicated to Immigration work and experienced in building H&C applications, but they're expensive. Free legal clinics exists in major cities and they're well worth the visit.
I wish her good luck.