http://www.youtube.com/watch?v=jqo_AyNPBfY
Apparently a young Russian in the US managed to get an interview with Allilueva in Wisconsin, which considering how secretive she is is quite an accomplishment. She refuses to answer direct questions about her father though and cut off contact when asked about her relationhip with Sergo Beria. It's in Russian but there are English subtitles for all Allilueva's comments.