That was pure luck, due to Mrs.Pendleton's chance visit to Flint House.

It was just chance that the girl did not encounter her aunt there.

She must have got away from Flint House shortly before Mrs.
Pendleton arrived.

But the strongest proof that there was no premeditation is to be found in the fact that Miss Turold made the journey openly, in a public conveyance." "And returned the same way," put in Dawfield.
"I confess that her action in taking that risk after the murder strikes me as remarkable," observed Barrant thoughtfully.

"But she would be anxious to return as speedily as possible, and perhaps she was aware that the last wagonette from St.Fair to Penzance is generally empty.