I’m writing a story which spans from 1987 to present day, the first half focuses on two characters, a boy ([name_m]Erik[/name_m] [name_u]Addison[/name_u]) and a girl ([name_f]Josephina[/name_f] [name_f]Grace[/name_f]). I’m pretty sure [name_m]Erik[/name_m] was in the Top 1000 in the 80s, I know it was definitely popular anyway. [name_f]Josephina[/name_f] was named after a [name_m]Joseph[/name_m] in the story, that’s why her name is a little out there. The second half of the story focuses on their children’s lives and growing up but I think their sibset may be really mismatched…I’m not sure. By the way, the names [name_u]Ashley[/name_u], [name_m]Brandon[/name_m], [name_m]Brian[/name_m], [name_m]Eli[/name_m], [name_f]Elizabeth[/name_f], [name_f]Ethel[/name_f], [name_u]Gary[/name_u], [name_u]Nick[/name_u], [name_f]Rachael[/name_f] and [name_m]Wyatt[/name_m] have already been used by other characters.
There’s [name_u]Aubrey[/name_u] [name_u]Jude[/name_u], [name_u]Madison[/name_u] [name_m]Robert[/name_m], [name_u]Mason[/name_u] [name_m]Dominic[/name_m], [name_f]Elissa[/name_f] [name_f]Brielle[/name_f] and [name_m]Wyatt[/name_m] [name_u]Rae[/name_u]. They’re a girl, twin boys, another girl and then a boy. I know [name_u]Aubrey[/name_u]'s name is really masculine but she is very tomboyish so I always imagined she’d have a sort of unisex name. I feel bad for using [name_u]Jude[/name_u] on a girl but I’m taking back [name_u]Madison[/name_u] so that cancels it out, haha. And I don’t normally like matchy twin names but for some reason, I like [name_u]Madison[/name_u] and [name_u]Mason[/name_u] together. [name_u]Madison[/name_u] would be named after his dad because his dad’s middle name is [name_u]Addison[/name_u]. I just love [name_u]Madison[/name_u] and [name_u]Mason[/name_u] on boys and I really want to use them. [name_f]Elissa[/name_f] [name_f]Brielle[/name_f] is named after both [name_f]Elizabeth[/name_f] and [name_m]Brian[/name_m], [name_m]Wyatt[/name_m] [name_u]Rae[/name_u] is named after the other [name_m]Wyatt[/name_m] and [name_f]Rachael[/name_f].
Is my sibset too mismatched? I actually think it sounds alright but you guys are more experienced in naming than I am so I thought it’d be better to ask for opinions 
They don’t sound mismatched to me at all.
The names go okay together, but they’re confusing when looked at as a sibset. If [name_f]Elissa[/name_f] was the only girl and the rest were boys, it would make a little more sense, style wise: surname-y names for the boys and a frilly name for the girl. Instead you have a girl named [name_u]Aubrey[/name_u] [name_u]Jude[/name_u] (pairing a unisex first name that is more popular for girls with a boyish middle), a boy named [name_u]Madison[/name_u] [name_m]Robert[/name_m] (an originally unisex first name that has pretty much gone to the girls with a masculine middle name), and a boy named [name_m]Wyatt[/name_m] [name_u]Rae[/name_u] (a unisex first name more popular with boys paired with a boyish name given a feminine looking spelling). Adding clearly gendered [name_u]Mason[/name_u] [name_m]Dominic[/name_m] and [name_f]Elissa[/name_f] [name_f]Brielle[/name_f] with their ambiguously gendered named siblings just adds to the confusion of the sibset as a whole.
if their parents enjoy the gender-confusion, that’s fine, but they should be more consistent about it. For example: [name_u]Aubrey[/name_u] [name_f]Jane[/name_f], [name_u]Madison[/name_u] [name_m]Robert[/name_m], [name_u]Mason[/name_u] [name_m]Dominic[/name_m], [name_u]Ellis[/name_u] [name_f]Brielle[/name_f], and [name_m]Wyatt[/name_m] [name_u]Ray[/name_u]. [name_u]Madison[/name_u] [name_m]Robert[/name_m] still sticks out a little since [name_u]Madison[/name_u] is just so much more popular for girls, but overall, I like that all the kids have surname-y first names and clearly gendered (for the most part – [name_u]Ray[/name_u] can be used for girls, too, but I would assume boy at first glance) middle names.
Of if you’re attached to [name_f]Elissa[/name_f]'s name, then I would suggest giving her sister a name that better matches hers. You say you like the name [name_u]Aubrey[/name_u] [name_u]Jude[/name_u] because the character is supposed to be a tomboy, but remember that parents have no idea what kind of personality their children will have when they are named, unlike authors. If you still want the oldest girl to have a boyish name, what about [name_f]Audrey[/name_f] [name_f]Jane[/name_f], nicknamed AJ? Or you could go with a feminine version of a boy’s name and have her go by a boyish name. [name_f]Judith[/name_f], nicknamed [name_u]Jude[/name_u] would work, for example. Or [name_f]Alexandra[/name_f], nn [name_u]Alex[/name_u]? [name_f]Georgia[/name_f], nn [name_m]George[/name_m]? Something along those lines.