@NeeNaw12 It might be obvious but if William is a family name too (it is for us as well!) , have you tried looking in your family tree for first name picks that might have come back into fashion again - thinking your or DH’s great grandparents or even great- great grandparents?
I also personally don’t think it matters for middle names if the family you most want to honour have 70’s names 🤣Most people won’t know your DD’s middle name/s so imo it doesn’t matter so much if it sounds dated.
First name is definitely important though - part of the reason I love William is the wide variety of nn’s ( Will, Billy, Liam), so other traditional names with good nn potential:
Antonia (Anna, Anya, Nina, Nia)
Victoria (Vita, Vika, Tia, Plum)
Christina (Kit, Kitty, Christy, Chrissy)
Helena (Nell, Leni, Ella, Ellie)
Josephine (Effie, Sephie, Josie, Posy)