How all-ages is Giant Days, Jim? My youngest (a sophisticated 8. but still 8) has been nagging me to get it since she read a teaser at the back of her beloved Lumberjanes, but without seeing anything too grown-up in that, the college setting made me think it might trend towards the more mature elsewhere. I'm reluctant to prevent her reading comics when the ineterst is there, but still...
Giant Days is PG13 stuff in execution, but storylines cover subjects like one night stands, excessive drinking, allusions to casual drug use, etc. If you have any comics reading apps, it might be worth checking if there are any free issues knocking about for preview purposes so you can judge for yourself.
A possible alternative might be the
Bad Machinery collections by the same author, which do a reverse-Torchwood in being an all-ages property spun off from a mature-readers original and which follow two groups of children in Yorkshire who have a boys vs girls rivalry based on who can solve more of the seemingly banal mysteries in their one horse town which almost always snowball into brushes with the supernatural. It's also drawn by Allison himself, who's never been what you'd call a
bad artist, but he did often deliberately change elements of his drawing style on Scary Go Round so that the overall effect was inconsistent, but here he sticks to a distinctive and bold style throughout, to the point that you may find reading his words over other people's art to be an occasionally jarring experience.