You don't need it bump mapped. That has got nothing to do with maternity clothing at all. Bump maps are to make "mesh" details in the texture, adding "shadowing" details so that parts will look as if they stand out - without having to model it. Bump maps have very limited uses, and only works to add details to the texture.
You need pregnant
morphs. Try
this link instead. It adds pregnacy morphs to nearly all the (adult female) maxis meshes

I think there might be some preg morph conversions for teen female too - just look in the teen female section in the community downloads here at insim. Look for the basegame mesh replacements. I'm not sure which mesh the teen gown uses, but the adult ones use the flowery nightgown as a base (morph for this is included in the link above). I did found a teen preg hospital gown somewhere too - but I'm not wuite sure where...
And I totally forgot about the chicken pox recolors... I'll see if I can put them up soon
