So, for Lavender. Alex went to fancy pants boy school at the same time she was at Athena, so there's potential for them to have been friendly types. Abby is obviously one of those mixed up in wizard shenanigans, too. I don't know the liklihood of their knowing one another yet, though.
And for Francis! Hannah has a minor in Philosophy and is a year behind Francis, so there might have been some overlap in classes or he might be a TA for one of her classes or one of these many options. Otherwise, I also have Rowena, who is also in her first year of grad school, so high five to them. There's potential that he's ran into Cassia during those hikes, since she spends as much of her time as possible out there.
OH there's probably other things, but my brain is mushy.