No. Committing procreation is not a qualification for any visa or immigration status anywhere in the world. Children derive rights from their parents. Parents derive no benefits whatsoever from their child.
Is she on an employment visa? Since she'll be taking time off work, she cannot even remain on her employment visa. Last day of full-time work is the last day her employment visa is valid. She will have to fly home before her 7th month, while she can still travel, and have her baby in her own country. She cannot remain!
IF you marry her, too late now. She cannot maintain her status on her current visa long enough to cover the entire Adjustment of Status period, currently running 6-9 months, sometimes more. She MUST continue working full-time if on an employment visa. Or attending school full-time if on a student visa. Or else she goes home. Remaining illegally now jeopardizes any change of status or future visa. She could arrange your immigration to her country when she gets home.
You realize that if you try to sponsor her as your spouse, your earnings requirements have just drastically increased as you must now prove you earn enough to support a household of 3, not 2 (assuming you have no other dependents).
You two have vastly complicated everything with this. She has no way to remain in US at this point. She goes home since she cannot remain in status on current visa. IF you marry, then after she returns home, you can apply for her spouse visa to reenter US. If you don't marry, she returns to her country & remains there.