It's not that she becomes grateful and nice towards you. She just snapped and lost her mind, now she thinks you're her dead(?) daughter. The daughter probably died from frenzy.

I already killed Cleric Beast, Father Cascoigne and Bloodstarved Beast - and then I spoke to the Old Lady.

I confirm that she is very kind after beating Cleric Beast, Father Gascoigne, Witch of Hemwick, Blood-Starved Beast, Darkbeast Paarl, Vicar Amelia and Shadow of Yharnam (Patch 1.05).

If you kill her, she says a dialogue "It was your... Father's blood" Is that new? Before i dont remember her saying that when killing her.

The sky has turned dark, I have beaten the shadows of yharnim bossfight and lit the lantern by byrgenwoth and immediately teleported back to the hunter's dream, she gives me sedatives even though I haven't even enterd the academy.

I used the wall jump early in the game and noticed that the man that gives you the Tonsil Stone and the Lonely Old Woman switch locations. She now is afraid of me and constantly tells me to leave her alone. Wondering if I can still send her to the chapel?

That strange creature sitting on the floor, or whatever it was, had me fooled. I immediately assumed it was a creature and struck it, killing it instantly. It wasn't until after when he said, "I just wanted to help..." that I realized I had possibly made an error. After having watched this, I realize there are all these twists and turns to the story. Honestly, it is aggravating because none of it is direct. When I arrived at the Suspicious Beggar, I did not even have the option of telling him to go anywhere, which is likely a result of these multiple NPC mistakes. Incredibly lame.

I have a theory the amygdala grabbed her while she was possibly searching the corpse of the man wearing the hunter set, that or the saw the amygdla, went mad, and killed herself.

When you kill her she says "it's your fathers blood" and drops one sedative.