I love [name_f]Susan[/name_f], and think it would be a nice choice for your daughter since it honors your mother. It may be unstylish right now, but on the plus side it’d be a recognizable yet uncommon name for your daughter’s generation.
For middle names you could go “traditional” like [name_f]Susan[/name_f] [name_f]Elizabeth[/name_f] or [name_f]Susan[/name_f] [name_f]Jane[/name_f], or use a more “current” yet classic middle like [name_f]Susan[/name_f] [name_f]Amelia[/name_f] or [name_f]Susan[/name_f] [name_f]Charlotte[/name_f] to help offset the dated feel.