Character 1: brown hair, hazel eyes, hesitant, & kind.
[name_f]Eva[/name_f] feels like a perfect fit! Honestly I wouldn’t change it for the world.
Character 2: [name_u]Blue[/name_u] eyes, dark hair, fair skin, & loyal.
I must admit; I find [name_m]Landon[/name_m] and [name_m]Eaton[/name_m] a little coded for prep-school, especially [name_m]Eaton[/name_m] (since it’s literally the name of a prep school).
I would suggest thinking about what aspects of these names you like and going from there!
My first thoughts were the similar [name_u]Linden[/name_u] and then [name_u]Hudson[/name_u]. They’re both on the softer side but have some structural strength. Maybe [name_m]Jasper[/name_m], or [name_u]Tristan[/name_u]? They’re perhaps a bit more common than [name_u]Linden[/name_u] or [name_m]Eaton[/name_m].
If you want to keep the surname appeal, perhaps [name_m]Watson[/name_m] or [name_m]Bennett[/name_m]? I’ve always been partial to nickname “Watts”, but that may not fit your character. You know him best!
For me, [name_m]Bennett[/name_m] feels like the best option. It’s proper enough (like [name_m]Landon[/name_m] and [name_m]Eaton[/name_m]), has a surname feel, but with a little more wiggle room for a mischievous nature.
Character 3: [name_u]Bright[/name_u] hair, freckled, cautious & logical.
Very Irish? [name_f]Siobhan[/name_f] is the classic. [name_f]Saoirse[/name_f] is popularized by actress [name_m]Ronan[/name_m], and [name_f]Sorcha[/name_f] is strong and bold. [name_f]Roisin[/name_f] (pronounced ro-[name_m]SHEEN[/name_m]) is my favorite; so silvery and sleek, but with that second-syllable lift! You might face pronunciation difficulties in the written space of a book though.
If you’d like something more subtly irish, [name_f]Isla[/name_f] and [name_f]Una[/name_f] are short and lovely, but perhaps too close to [name_f]Eva[/name_f]. You could go a little farther afield in the UK for [name_f]Tamsin[/name_f], [name_f]Iona[/name_f], [name_f]Gwen[/name_f] and that related host of names.
I second [name_u]Rowan[/name_u] as well! Any red-haired [name_u]Rowan[/name_u] is a character I want to know.
Character 4: [name_m]Young[/name_m], crazy, wild.
You’ve got some great suggestions here! I give a strong second to [name_u]Rory[/name_u] and [name_u]Blaise[/name_u].
I’d also like to add [name_u]Cass[/name_u] because of its similarity to [name_u]Cade[/name_u] and its single syllable resonance with [name_u]Finn[/name_u]. It’s always a good idea to vary syllables and ending letters between a set of names. If you did go with [name_u]Finn[/name_u], other -n ending names like [name_u]Rowan[/name_u], [name_f]Gwen[/name_f], [name_u]Tristan[/name_u], [name_m]Landon[/name_m], etc become a little less desirable.
[name_u]Alfie[/name_u] has a lot of energy but may feel a little brief. [name_m]Ivo[/name_m] is far more unusual but packs such a punch! [name_u]Adair[/name_u] is one of my favorites, but I do love the idea of a monosyllable for character 4 ([name_u]Finn[/name_u] or otherwise!).
Here are my top suggestions for each name. They all offer a decent degree of variation in ending letter and syllable count!
1: [name_f]Eva[/name_f]
2: [name_m]Jasper[/name_m], [name_u]Tristan[/name_u], [name_m]Bennett[/name_m] (1 or 2 t’s)
3: [name_f]Tamsin[/name_f], [name_f]Gwen[/name_f], [name_u]Rowan[/name_u]
4: [name_u]Cass[/name_u], [name_u]Rory[/name_u], [name_u]Blaise[/name_u]
A couple combinations to consider:
[name_f]Eva[/name_f], [name_m]Jasper[/name_m], [name_u]Rory[/name_u] & [name_f]Gwen[/name_f] (my favorite)
[name_f]Eva[/name_f], [name_m]Bennet[/name_m], [name_f]Tamsin[/name_f] & [name_u]Cass[/name_u]
[name_f]Eva[/name_f], [name_m]Bennett[/name_m], [name_u]Rowan[/name_u] & [name_u]Blaise[/name_u]
You could also try these (which are Irish)