I own the Saleya PM. It is meant to be a handheld bag, however I can fit it on my shoulder quite comfortably--although like RoseMary said it is a bit snug with a heavy coat...but I bought mine Azur so I will never use it when I am wearing a coat since I use it as a Spring/Summer bag only.
I would indeed prefer the Saleya in the MM or GM size for a new Mom as compared to the Palermo. The Palermo has the hand held straps and that detatchable long strap and I think that will get way to cumbersome and bothersome. Go for one of the Saleyas.
I think I'll go for the MM but I read somewhere in the forum that the rolled handles aren't that comfortable for the shoulders. So I'm still deciding if I should get one. Anyway I've just purchased a Goyard and I'll see what's all the hype about this brand and will post up my review soon.