Catelyn/Cersei parallels

[starklinson]

Despite being enemies, these two characters have had similar experiences, especially early on in the series.

• Their mothers both died in childbirth, causing a hardening of their fathers and an added difficulty in their families.
  
• Eldest child.
  
• Both had a arranged marriages for political reasons and had their hearts broken early on in the marriage (Ned coming back with Jon, Robert still in love with Lyanna).
  
• Their fathers had originally different plans for their daughters' betrothal (Catelyn to Brandon, Cersei to Rhaegar).
  
• Both watched their eldest sons die, who both were in positions of power at their time of death.
  
• Despite their high ranking, both felt some degree of frustration with their society and how their political intellect was often ignored for their gender.
  
• Were taught (arguably) toxic ideals as children.
  
• Their second children are daughters (Myrcella and Sansa).
  
• Husbands were best friends.
  

Any others?

[SeanF]

Catelyn (and her brother) have far more sympathy for the Smallfolk than any of the Lannisters do. So, I'd dispute that she was brought up with "toxic" ideas.

[The Sleeper]

There are more contrasts than parallels. For instance Cersei brings up the differences between her education and treatment in comparison to Jaime. On the other hand Catelyn refers to how she played the role of a son, while Hoster lacked male heirs and later how she was called to play the role of lady when her father died.