What a beautiful name!
I love [name_m]Conrad[/name_m] with [name_f]Ida[/name_f]. 
Both [name_f]Cleo[/name_f] and [name_f]Willa[/name_f] work well in my opinion so you can’t go wrong!
I few ideas:
[name_f]Sally[/name_f]
[name_f]Daisy[/name_f]
[name_f]Rosa[/name_f]
[name_f]Eve[/name_f]
[name_f]May[/name_f]
[name_f]Pearl[/name_f]
[name_f]Alice[/name_f]
[name_f]Nora[/name_f]
[name_f]Lucy[/name_f]
[name_f]Thea[/name_f]
[name_f]Hazel[/name_f]
[name_f]Olive[/name_f]
[name_f]Pippa[/name_f]
[name_f]Sylvie[/name_f]
[name_f]Phoebe[/name_f]
[name_f]Flora[/name_f]