Oddly, I actually already know the answers to this question! Usually I have to think about it.
Marietta: is a strawberry rhubarb pie because that's my favourite kind of pie. ;p Aside from that, I think it's the kind that you either like or you don't and she's sort of the same way.
Stacey: is a homemade apple pie just because...why did I ask why? It just suits her, yeah? Simple and a bit ordinary as pies go, but always good.
Sylvie: is a French silk pie because 1) she's part French and 2) it's very indulgent.