Giselle is IMHO one of rare names everybody knows of and rarely anybody use it. I'm not biggest fan of ballet, but I don't mind associations, but would love to avoid name sounding like we're biggest ballet fans. I'm also fine with German, French and English pronunciation, but will pick one closer to French, zhiz-EL. We don't have problem with meaning, it could also mean pledge. Problem is we love lot of show stopper names and name combo looks heavy and attention seeking.
We were thinking something along lines of
Cordelia Giselle
Giselle Amoret
Giselle Rosamund
Giselle Lorena
Beatrice Giselle
Giselle Romilly
We both love Beatrice and Cordelia, but I would rather pick Giselle and call her Giselle.