The AFL Season Guide lists those with 7 or more in a quarter. I can't find anything more online:-I've only found R2 2015 for Kennedy.
5 in a half is more common, but 5 in a quarter seems quite rare.
8 goals:
Harry Davie (Melbourne): Q4 v Carlton R14 1925
Gordon Coventry (Collingwood): Q1 v Hawthorn R13 1929
Bob Pratt (South Melbourne): Q4 v Essendon R3 1934
Bob Pratt (South Melbourne): Q3 v Carlton R13 1934
Kelvin Templeton (Footscray): Q4 v St Kilda R13 1978
7 goals:
Harold Robertson (South Melbourne): Q4 vs St Kilda R12 1919 (this is the game mentioned in a couple of posts near the bottom of the previous page)
Bob Pratt (South Melbourne): Q4 v Footscray R15 1934
Jim Baird (Carlton): Q4 v Fitzroy R15 1942
Fred Fanning (Melbourne): Q2 v St Kilda R19 1947 (the game where he kicked 18)
John Coleman (Essendon): Q4 v St Kilda R18 1950
Doug Wade (North Melbourne): Q4 v Collingwood R21 1974
Jason Dunstall (Hawthorn): Q4 v Geelong R1 1990
Peter Sumich (West Coast): Q3 v Footscray R13 1991
Scott Lucas (Essendon): Q4 v West Coast R22 2007