Hi Allison! I have a few options (:

Cameron Gillenwater is a fourth year, but Maggie might know him if she's friendly with Sloane Bixby! He's very friendly with the majority of the Gryffindor girls in the year beneath him, and also plays on the quidditch team!

Archie Diggory is one of my first years, and he's best friends with Sunday Fudge (Maggie's dorm-mate!). He's generally studious and ~bookish, but he loves adventures and spent many of his early years abroad with his magical archaeologist parents! They might know each other from Hogsmeade as well!

Flora Mulciber and Hortense Selwyn are around her age, but likely wouldn't pay any mind to her. Hortense tends to keep to herself or her family, and tries to keep a low profile. Holly Scrimgeour is a third year and plays the role of antagonist in many students' lives, so that's an option, too!

Frida Lestrange and Orinda Ruskin also exist for your needs going forward (Frida's a prefect and Orinda is a tardy mess!), but I don't see a potential for a preexisting relationship with either ^^