Thanks for the comment. In fact, I did mean to use 'Gerard' and not 'Gerald', which have different roots, the former being the German 'Gerhard', as is above, and the latter, being the German 'Gerhold'.
"Mitzi" is a diminutive (or nickname). The German name for Mary is "Maria" or "Marie". Also, I believe that Renate is the female "Renee" in English (or rather, French), not the male "Rene".
Thanks for your comment. I reserve the possibility of utilising dimunitives for the sake of increased difficulty. The 'Rene' was a typo and has now been corrected.