Be it in bad taste to say that Catelyn Stark's narrative in #ASoIaF comes to a screeching halt? Mayhaps you feel it is if you are a big fan of Lady Catelyn. However, if you are a big fan of Lady Catelyn, this is likely not a podcast you will enjoy listening to. That said, has anyone really gone on record saying that Catelyn Stark is their favorite character from A Song of Ice and Fire or Game of Thrones? Not bloody likely.
If there was a House Dumb-Idiot of StupieLand, the matriarch would be Catelyn Stark (or Tully, as it were) and the sigil for House Dumb-Idiot would be a crude depiction of the synapses in Catelyn's brain lighting up as she takes advantage of a situation to further her personal agenda of escaping from the North and stumbling into her own circle of power in the South.
To back up a bit to before he becomes the Lord of Riverrun- Hoster Tully married Lady Minisa Whent of Harrenhal while his father ruled The Riverlands, before The War of the Ninepenny Kings. Together, Hoster and his wife Minisa had three children, though there were three more that did not survive past infancy. The timing isn't very clear as to if Catelyn was born before the death of her two brothers, though it seems unlikely she was. It is clear that Lady Minisa bore Hoster two sons that did not survive and therefore Hoster came to regard Catelyn as his heir. Another daughter followed Catelyn- Lysa, and finally a son- Edmure. Lady Minisa bore another son after Edmure, but Minisa did not survive that childbirth and the son died along with her. As reflected upon by Catelyn in her POV, Hoster Tully truly loved his wife and was deeply scarred and saddened by her death, missing her and just as sad decades later.
The Princes That Were Promised make a pit stop on the Catelyn Stark Memorial Highway- a (fake) highway with tolls every 20 yards, as well as poorly engineered tressels and footbridges that are built so low the tops of SUVs are damaged and 20 car pile-ups occur daily. Before the events of ASoIaF and shortly after a 12-year-old Catelyn Tully was promised to Brandon Stark of Winterfell, Hoster Tully, The Lord of Riverrun and Lord Paramount of the Riverlands, negotiated another marriage pact with Tywin Lannister, The Lord of Casterly Rock and Warden of the West. This marriage would have been more lucrative for Hosterthan the shipment of his eldest daughter to the cold, hard North.