Here's a way to get a time of
12 minutes
Arranges conversations by
spliting the party into two groups of five, one with Al and one with Jane, and have each group split into 2+3 in each of the ten possible ways.
You can get another two minutes by
Having each group of 5 in a conversation.
and
Doing the same but splitting a person from each group (not Jane) into a conversation pair, leaving each half with 4.