canada landing

Hi:
We just receive a letter from canada consulate in NY, they asked us to send our passport in order to get stamp. In our case, my common-law partner is the main applicant,and I am attaching to her case, however, a days ago, we just found out my partne is pregnent about six weeks. I dont think she can travel to land in canada, b/s we want our baby born in here US. my question here is can we sent our passport to get permanent visa stamp and only me to go landing? (b/s my partner doesnt care maple card since she already has green card) b/s she is main applicant, I am afraid the canadian border wont let me landing.
does anyone has landing to canada separately?
please share