[name_m]You[/name_m] daughter has a magnificent name!
Both options are absolutely gorgeous. I slightly prefer [name_f]Beatrice[/name_f] [name_f]Margaret[/name_f] [name_f]Rose[/name_f], but you can’t go wrong. [name_f]Rosalind[/name_f] is a beautiful idea to honor your sister, too.
I would go with the shorter second middle name because the other two names are already quite long. In this case, I believe [name_f]Rose[/name_f] offers a better flow.