They wanted to wed her off.
Announced that there would be soon a marriage. Another time, a marriage between a Dragon and a Trout.
She remembered the tales of her uncle: How he and Aelinor Targaryen met the first time?
How a Dance with Dragons had changed his unusual life, as he used to adress jokingly the scene in the royal court.
And even two civil wars weren't enough to separate them. To force them to neglect this relationship. Even more it turned out as an opportunity, who saved her family!
Where might the Riverlands stand without Lord Daryn Targaryen, a simple poet, who saved probably thousands of Riverlanders from getting killed by King Baelor II. by ties of relationship and an emotional letter towards the realm.
The marriage between him and Princess Aelinor Targaryen made Westeros a better place - and only the death of his wife divorced him from her.

Edlyn was like her uncle not the person to accept a destiny, being chosen by her father or mother.
And yet, she disgusted the opportunity of marrying a dragon.

If she was honest, she never felt like at home, when she watched from the distance, a hooded figure, smoke arising from her chamber. Her home was never at Riverrun and never this family.
She always had asked Daryn Targaryen, how he was able to live among his brothers, how he was able to still remain patient upon a bunch of children, whose destiny was already chosen by their parents.
In fact it was ironic, that she had the luck of being born as the firstborn child of the Lord of Riverrun - but yet wouldn't inherit anything due to her brothers. Even a third one has now been born - it seemed as if the Seven wanted to on her head and demonstrate her even more, onto which place she belonged.
Well, obviously it wasn't Riverrun - it never was. Her mother made her already clear that she would some day have to leave this place due to the plans of her parents.
And yet, it wouldn't be Summerhall.

Not that Edlyn hated Daeron. In fact, they met only for a short time and he probably would have been a better option than the war-mongering Lord Bracken, the joyful Lord Piper or any other disgusting Riverlander noble in her eyes, to whom her mother would have wed her off. Daeron Targaryen, heir of Summer Hall, son of a former Prince - the political opportunities would have been marvelous for her and her family at some point.
She might have admitted to that, it might have been more comfortable - but unlike Rhaenyra, her cousin, Edlyn disgusted comfort as much as she disgusted being dependent on a male being. It already had shocked her to hear, that even her cousin had married the Arryn Prince instead of doing, what she once told Edlyn: Staying on her own feet, choose the man she loves, inherit and dominate.
All Rhaenyra dominated now in Edlyn's eyes was a golden cage, as she failed to make herself independent.
And at this day, the Tully woman had decided to change her fate in a drastic way.
A way, dangerous and probably leading her to her death - but a way of freedom and the independence, she had dreamt of.

She ran unnoticed through the village in front of Riverrun with it's booming market square. Most of the guards, who might have recognized her, should they have looked under the hood were rather paying attention to the window of the burning chamber and alerting the town garrison than looking upon a person, dressed like the usual militias of the province - and even then it might have been harder to recognize her yet, as Edlyn had taken care that she would not simply vanish from her 'home'.
Rather Edlyn Tully was dying in said chamber, burning alive like it was rumored about her uncle, the former Lord Lothstone of Harrenhall - or at least she pretended to die.

There was no reason for her to hold up the image of Edlyn Tully, the masquerade she had shown the world.
the alliances of some old, ancient houses, the plans of her family, the pretending of her being a real lady upon a noble court!
The corpse of the female beggar, whom a friend of hers with the knowledge of an alchemist hided inside the room for this moment to happen, in her clothes would be enough to convince the world of her having passed away in a horrible way. Luckily the woman was already dead, when Alester had smuggled her into the castle. According to him she died already out of starvation and was already thrown into a pit, where a pile of beggars was already laying - honor upon the banners of House Tully, but the poorest people in society were treated in afterlife as in every usual village or city in the kingdom.
Either way, she didn't care too much about it - those days a lot of people have died in Westeros. No matter if it is actually that woman or that shemeing Lord Hand in the capital - not even the whole gold of the Iron Bank of Braavos was able to by-pass the Stranger!

The woman approached slowly the wagon of the alchemist and entered it, after the man had recognized the silver sigil ring on her hand.
A ring, she would later feed to the trouts.
The last step of the death of Edlyn Tully has been executed.
The first step upon her rebirth in the land, she would call rather home than the official home of Edlyn Tully, would follow afterwards.