When it comes to “too close”, I feel that a theme should be subtle and not blatantly obvious. I’m personally not a big fan of all girls with the varying flower names (no for [name_f]Rose[/name_f], [name_f]Lily[/name_f], [name_f]Daisy[/name_f]) or precious stone (no to [name_f]Opal[/name_f], [name_f]Pearl[/name_f], [name_u]Ruby[/name_u]). That seems to happen a lot. I would vary it if it were word or botanical names (yes with [name_f]Wren[/name_f], [name_f]Poppy[/name_f], and [name_f]Marina[/name_f]).
What I prefer is more layered. Television is a great example of often what not to do. There used to be a show where all the sisters had boyish nicknames that were just too cutesy (ick to [name_u]Alex[/name_u], [name_u]Georgie[/name_u], [name_u]Teddy[/name_u]). Another had a father named [name_m]Victor[/name_m] and mother named [name_u]Nikki[/name_u] who had a son named [name_m]Nicholas[/name_m] and [name_f]Victoria[/name_f] who had a grandson named [name_u]Noah[/name_u].
When I think of style I often think of sex. Is this a girly-girl name ([name_f]Allegra[/name_f], [name_f]Suzette[/name_f], [name_f]Mirabelle[/name_f])? Her brother’s name should have a more macho quality ([name_m]Magnus[/name_m], [name_m]Boone[/name_m], [name_u]Rex[/name_u]) instead of something more unisex ([name_u]Rory[/name_u], [name_m]Hayes[/name_m], [name_u]Asa[/name_u]). If you go for unisex sames for one child, I feel you shouldn’t steer too masculine or feminine with the later siblings. [name_m]How[/name_m] masculine a name is for a son should be related to how feminine you daughter’s name must be.
Names sounds are important. I feel that endings especially work. For example, [name_u]Juniper[/name_u] would have a brother named [name_m]Fletcher[/name_m] or [name_u]Bryn[/name_u] with [name_m]Darwin[/name_m]. It’s easy for sister [name_u]Sutton[/name_u] to have a brother named [name_m]Jefferson[/name_m]. Having the same initials is too simplistic (ew to [name_f]Celia[/name_f], Claria, and [name_f]Claudia[/name_f] or no to [name_f]Adele[/name_f], [name_u]Arlo[/name_u], and [name_f]Adrienne[/name_f]).
Popularity is hard to gage what the future may bring. If it’s a really common name like [name_m]Michael[/name_m], it’s best to go with [name_f]Jennifer[/name_f] than [name_f]Edna[/name_f]. [name_f]Edna[/name_f] would do better with a brother like [name_m]Burton[/name_m]. What was once popular in the 80s like [name_f]Tiffany[/name_f] should have a brother named [name_u]Blake[/name_u] or sister [name_u]Alexis[/name_u] instead of more current [name_u]Jayden[/name_u] or [name_u]Sierra[/name_u].
When it comes to classics, I’d stick with the same vibe. Biblical seems to be popular but you may need to read the text since [name_m]Joseph[/name_m] and [name_f]Mary[/name_f] would make horrible sibset but [name_m]John[/name_m] and [name_f]Mary[/name_f] would be better. [name_f]Eve[/name_f] and [name_f]Lilith[/name_f] wouldn’t be so good together as sisters but either one could have [name_m]Samson[/name_m] for a brother if you’re up for it.
Here are a few other themes I can think of. If one of your first child has a last name for a first name, it’s best to go subtle (brothers [name_m]Edison[/name_m] and [name_m]Lennox[/name_m] with sisters [name_u]Sloane[/name_u] and [name_u]Jensen[/name_u] instead of [name_m]Archer[/name_m] and [name_m]Tanner[/name_m] with [name_u]Madison[/name_u] and [name_u]Addison[/name_u]). When it comes to image pass on brother [name_m]Lincoln[/name_m] and sister [name_u]Kennedy[/name_u] or sisters [name_f]Ava[/name_f] and [name_f]Marlena[/name_f]. What I like was someone who named their daughter after singers like [name_f]Ella[/name_f] and [name_f]Astrid[/name_f] or [name_u]Ray[/name_u] and [name_u]Lionel[/name_u].