How about naming her [name_f]Martha[/name_f] and calling her [name_f]Daisy[/name_f]? [name_m]Or[/name_m] [name_f]Margaret[/name_f] → [name_f]Daisy[/name_f].
[name_f]Martha[/name_f] Helena!! → A great way to honor helen but put your own spin on it!
[name_f][/name_f][name_f]Martha[/name_f] [name_f]Lucille[/name_f]
[name_f][/name_f][name_f]Martha[/name_f] Marylen (combo of [name_f]May[/name_f], lucy, mary + helen)
I was going to go in same direction as pp suggest [name_f]Martha[/name_f] [name_f]Helene[/name_f] [name_f][/name_f]- maybe flows a little better than [name_f]Helen[/name_f].
[name_f][/name_f]I think [name_f]Martha[/name_f] [name_f]Beatrice[/name_f] is lovely!
[name_f][/name_f]Good luck