Too often preg shots show the mother with a somber expression.
You allowed the subject to show joy, as it should be.
First one, lighting could have been a tad less harsh, you lost some of the skin tones.
Second one, skin tones are lovely.
Subject(s) probably didn't want to go nude, but the pants in both shots really detract and look tacky. Nude would have been the way to go with the 'privates' shaded or darkend to maintain modesty.
Fact is, unless all parties involved are VERY open minded, this is a tough assignment, especialy for a first time.
Bottom line, IMHO, you did very well.