Neighbours

[Dombo]

Point out to her that whereas any herbert is allowed to fix plumbing, lecky stuff must by law be done by a qualified professional electrician. Had it not, and a fire ensued in your ceiling space (her floor space) she would have suffered rather more than you as heat and smoke rises.
Depending on how neighbourly you want to be, perhaps suggest splitting the bill with her. If she refuses, at least you won't have to bother keeping an eye on her place when she's away, taking in parcels etc. She'll understand.

[Marky Mark]

I would of done it for free for you Sean

No question of who pays then.

MM

[Andrew G]

Any chance you can get the electrician to drop you a note to confirm that it was water damage due to a leak from the flat above?