I think [name_f]Zinnia[/name_f] is beautiful and I don’t think the connection to the mother in the book [name_f]Matilda[/name_f] is a dealbreaker at all.
[name_f][/name_f]Still, here are some suggestions:
[name_f][/name_f][name_f]Azalea[/name_f]
[name_f][/name_f][name_f]Calla[/name_f]
[name_f][/name_f][name_f]Cassia[/name_f]
[name_f][/name_f][name_f]Sienna[/name_f]
[name_f][/name_f][name_f]Zara[/name_f]
[name_f][/name_f][name_f]Zenaida[/name_f]
[name_f][/name_f][name_f]Zina[/name_f]