I think it depends on what you plan to call her most of the time.
If she’s going to go by [name_f]Josephine[/name_f] or even [name_u]Jojo[/name_u] or Phina or something, then I’d go with [name_f]Daisy[/name_f]. [name_f]Josephine[/name_f] is lovely but it is a bit heavy and [name_f]Daisy[/name_f] really lightens it up. [name_f]Josephine[/name_f] [name_f]Daisy[/name_f] is beautiful together.
If you’re going to call her [name_u]Josie[/name_u] the majority of the time, and [name_f]Josephine[/name_f] will only be her formal name. Then I’d go with [name_f]Leah[/name_f]. [name_u]Josie[/name_u] [name_f]Daisy[/name_f] is super cutesy, and [name_u]Josie[/name_u] [name_f]Leah[/name_f] sounds great. I don’t think the flow is bad with [name_f]Josephine[/name_f] [name_f]Leah[/name_f], it sounds very calm and stable.
Perfect in combining both [name_f]Daisy[/name_f] and [name_f]Leah[/name_f]. Sweet and mature. I think this is would be a good choice for your daughter.