[ghaff]

It's ambiguous in the film. Karen Allen was 30 when Raiders was made so we could be talking college age which still fits with the dialogue for an affair with a 10+ year older man at that age.

Of course, it's not really remarkable in the film because, in addition to both of them being 10 years older, it's very much a norm in Hollywood to have younger (so long as not too young) women and older men.