Yes that's right
(I'm french)
Maguy is the diminutive of Marguerite (Margaret in English , Margrethe in Danish ... )
And if I remember well , Daniel mother's name is Maguy ....
And for the pronounciation of Grace .... that's hard to explain .. but we say it : gr-A-ce (not Gracie .... but Grace ... just like ..... the word grace , grasse or the city in the south of France : Grace !! )
That's very very rare to meet little girls with that name (Grace) .... even Maguy is rare .... more than Grace !
Sorry , the city in the south of France is GRASSE of course , and not Grace as I've said
A city near Cannes