Already the Codex Alexandrinus and some other MSS of the LXX as well as the old Syriac translators clearly found the expression "mother's house" difficult. They have smoothed the text here.

Cf. J. de Waard & E. Nida A Translator's Handbook on the Book of Ruth London: UBS, 1973 p.12; cf. A. Rahlfs [ed] Septuaginta Stuttgart: Deutsche Bibelgesellschaft, 1935 & 1979 ad loc..