My first thought when I see
Isabeau is a vampire matriarch character created by
Deborah Harkness called
Genevieve Melisande Helene Ysabeau
Aude de Clermont known now to most as Ysabeau. I know it is spelled differently but pronounced the same.
I love
Isabeau because of positive associations with the character and it sounds close to
Isabel which I like a lot.
Mirabeau is more whimsical, more fantasy than
Isabeau for me but if I came across it in real life or fiction I may feel differently.
Don’t take criticism from someone you wouldn’t take advice from