Night 1-
Wren 12
Jenni 4
Night 2-
Wren 16
Jenni 9
Night 3-
Wren 20
Jenni 14
Night 4-
Wren 24
Jenni 19
Night 5-
Wren 28
Jenni 24
Night 6-
Wren 32
Jenni 29
Night 7-
Wren 36
Jenni 34
Night 8-
Wren 40
Jenni 39
Night 9-
Wren 44
Jenni 44
It would be 9 nights.
Graph using (x) and (y), Wren being (x) and Jenni being (y)