I'm 50/50 (no pun intended) on Kanan being the dad myself. Would be a good twist if the rest of the series hasn't been a circus.
But I've known quite a few women who ended up fucking/pregnant by I dude they say the didn't care for or "acted" like he wasn't shit. So the idea ain't baseless. I'm sure the majority of us have run into that scenario before. It ain't like Tasha hasn't shown signs of thinking with her pussy.
Tasha has legit reasons to hate him, tho.
Kanan stunted Ghost' growth as drug dealer, tried to kill him and destroy his business that feeds her family, is responsible for the corruption of her son, and the death of her daughter.
The nigga came thru penthouse with flowers and she had the toolie in her draws.
And hypothetically, she was trying to run away with his son. How would she have broke it to him that she used to fuck his dad back in the day and that his stepchildren are actually his brother and sister?
Doing that angle just changes too much shit for no reason.