I love the name Alethea! I know someone with a daughter named Alethea and every time I hear it I absolutely love it. So unique and pretty. Alethea Frances… Alethea Catherine… love them!
I really like [name_f]Alethea[/name_f]! [name_f]Alethea[/name_f] [name_f]Frances[/name_f] is my favourite combination, but I also quite like [name_f]Alethea[/name_f] [name_f]Margaret[/name_f] and [name_f]Alethea[/name_f] [name_f]Mary[/name_f].
I would go for [name_f]Alethea[/name_f]. It’s a lovely and rare name. I really like the sound of [name_f]Ariana[/name_f] but I would worry about constant [name_f]Ariana[/name_f] [name_f]Grande[/name_f] comments.
I love [name_f]Alethea[/name_f]! So pretty and ethereal sounding, I like [name_f]Ariana[/name_f] but I know quite a few little Ariana/Ariannas so I like the more uniqueness of [name_f]Alethea[/name_f].
As for middle names I like your style of more traditional middles with a more unusual first name. I really like [name_f]Alethea[/name_f] [name_f]Charlotte[/name_f].