Combine strawberries and the next five ingredients, tossing lightly to combine. Cover and chill up to 2 hours.
To make whipped cream, whisk cream to form soft peaks, then add sugar and vanilla. Whisk again to form stiff peaks.
Scoop 1/2 cup sorbet into each of 6 serving dishes. Spoon two-thirds cup of berries over sorbet in each dish. Top with whipped cream and walnuts.