A.T. Robertson Commentary 1 Corinthians 7:34

"and is divided. [So] also the woman that is unmarried and the virgin is careful for the things of the Lord, that she may be holy both in body and in spirit: but she that is married is careful for the things of the world, how she may please her husband." — 1 Corinthians 7:34 (ASV)

And there is a difference also between the wife and the virgin (κα μεμεριστα κα η γυνη κα η παρθενος). But the text here is very uncertain, almost hopelessly so. Westcott and Hort put κα μεμεριστα in verse 33 and begin a new sentence with κα η γυνη and add η αγαμος after η γυνη, meaning "the widow and the virgin each is anxious for the things of the Lord" like the unmarried man (ο αγαμος, bachelor or widow) in verse 32. Possibly so, but the MSS. vary greatly at every point. At any rate Paul's point is that the married woman is more disposed to care for the things of the world. But, alas, how many unmarried women (virgins and widows) are after the things of the world today and lead a fast and giddy life.