Is there a way to get the health card and its benefits if she give birth in Canada without the 3 months waiting period.
Not if you are planning on living in Toronto. They make no exceptions to the 3 month waiting period. Even if you had at some point stayed for 3 months and applied for your health cards, you would have lost your coverage again being outside Canada that much. OHIP makes it a requirement that you stay for at least 5 of the first 6 months as you qualify to get your OHIP and after that at least 6 months a year.
If you were to move to another province, not BC or NB either and not Ontario, the health care there might consider that you never actually settled in ON and may treat your move as an international move and give you first day coverage. However, all health care systems in Canada require living in the province for 6 months a year to be eligible for their health care so if you leave after less than 6 months, they may decide that you never should have been eligible in the first place and you may get backcharged for the services you received.
Quebec does have a 3 month waiting period but makes exceptions for pregnant women. However, I have also heard of a case where a PR family was refused coverage for the birth of their 2nd child in Quebec as they had not stayed in Quebec after their first child had been born there.