Help with character surnames please?

I’ve already considered a couple surnames (Porter, [name_u]Olsen[/name_u], [name_u]Kendall[/name_u], etc.), but I haven’t quite decided and I thought it would be good to ask for some more ideas. [name_f]My[/name_f] characters’ names are [name_m]Ethan[/name_m], [name_u]Sierra[/name_u], [name_m]Matt[/name_m], [name_m]Lucas[/name_m] and [name_u]Avery[/name_u] (who are siblings, so they’d have the same surname). If it helps, all of these characters are teenagers and [name_m]Lucas[/name_m] and [name_u]Avery[/name_u] are from a richer typical suburban kind of family. Any suggestions would be appreciated, thanks!

[name_u]Porter[/name_u], [name_u]Olsen[/name_u], and [name_u]Kendall[/name_u] are great ideas! I like giving characters surnames that are familiar but not too popular, and those fit the bill perfectly!

Some more ideas (depending on the ethnic backgrounds of the characters, some may or may not fit)
[name_m]Kimball[/name_m]
[name_u]Parker[/name_u]
[name_u]Collins[/name_u]
Birdwell
[name_u]Sawyer[/name_u]
[name_u]Rivera[/name_u]
[name_m]Fischer[/name_m]
Goldman
[name_m]Lewis[/name_m]
Alvarez
Yang
Schmidt
[name_m]Newman[/name_m]
Hopkins
[name_m]Walsh[/name_m]
Welsh
[name_m]Caldwell[/name_m]
[name_m]Frasier[/name_m]
[name_u]Rhodes[/name_u]
[name_u]Cohen[/name_u]
[name_f]Summers[/name_f]
[name_m]Larson[/name_m]
[name_u]Sweeney[/name_u]
[name_u]Callahan[/name_u]
Salazar
McAdams
[name_f]Medina[/name_f]
[name_u]Reynolds[/name_u]
[name_m]Simmons[/name_m]
[name_m]Russell[/name_m]
[name_m]Hughes[/name_m]

Based on [name_u]Porter[/name_u], [name_u]Olsen[/name_u], and [name_u]Kendall[/name_u] I mostly suggested European-originating surnames, but I added in a few others that I felt had a good balance of recognizable but not super common.