Here’s something you might not of considered, but should! 

Not only does the surname sound good with the character’s name, but does it sound good with whoever the character is going to end up with? Did you think of that? 

It’s a silly little detail, but I kind of obsess over this. It’s weird that I obsess over this, because in the world my book takes place, changing your surname isn’t standard, in fact, it’s pretty unusual, but I do. Because then I have that option. 

I started doing this because my protagonist’s name is Itazu Warren, and her father was initially called Henry Brown. The surname Warren came from her mother, Charlotte Warren, but to avoid questions I changed his name to Henry Warren, story wise, it makes sense he would change it after becoming the sole guardian of his daughter as a show of unity or something, I dunno. 

And once I did that, I knew I would do it with all my pairings. 

Elizabeth Owen and Emily Hill. 

Both Elizabeth Hill and Emily Owen sound perfectly fine. 

So yeah, if you want you can compare surnames of character’s  in my book to see if they have any change together or not.