ALRIGHT. so. i feel like —- as both the writer of joanna lannister AND a lifetime defender of the lannisters as a whole —- i should share some of my thoughts on how joanna’s presence would have HEAVILY impacted the way tywin parented their children, thus changing their individual outcomes.

it’s obvious the way joanna impacted tywin as she is remembered throughout the series. ( the best of him died with her ;  [tywin] was ruled at home by his lady wife ;  etc. ) this makes it more than reasonable to think that, while tywin would still have been a harsh man, he could have been a truly LOVING FATHER. which would have changed EVERYTHING.

jaime, i feel, is already VERY MUCH like his mother ; we begin to see his compassion for others particularly after acok and watch it grow stronger beyond that. he is not a WEAK man, but rather the kindest and even most warm-hearted of his siblings ( if that could truly be said for ANY OF THEM ). all of this, without joanna even being present for the MAJORITY OF HIS LIFE.  who might jaime have been had he been free from tywin’s cruelty, or had the ability to seek his mother’s guidance rather than his father’s or cersei’s ?  it’s intriguing to think about. still the kingslayer, no doubt, but with a touch less of arrogance, perhaps ? 

tyrion’s life would have been DRASTICALLY different, of course. he would never have suffered the abuse of his father and older sister, who always blamed him for joanna’s death ;  which, ultimately, would have changed so much of who he is as a character. in truth, joanna would have babied her youngest son, especially because of his disability. although this wouldn’t have altered tyrion’s natural wit or cleverness, he might have lost much of the BITTERNESS and HATRED he holds towards his family. 

and, finally, cersei. cersei’s relationship with joanna is one of my favorites to think about for multiple reasons ;  namely, because of how joanna’s presence would have changed cersei’s ideas toward her own femininity. throughout the books, we see cersei hating herself solely because she is a WOMAN ;  an idea instilled in her by tywin, who always treated her as less than equal to jaime. although joanna could never have tamed the wildfire of ambition within her daughter, she could have been the feminine figure cersei needed to truly PROSPER. 

if joanna had survived, we would be looking at a very, very different pride of LIONS.