Last time

Yes, for the most part.

She's referring to the most immediate time she last saw her mother, but is also referring to previous visits.

There is room for clearer expression, but it's clear enough.

"Last time" means a single occasion, but "operas" implies an ongoing situation. I think it should say "Before".

Thanks, Infrablue and Jewels.

Would "Formerly" work?

I'd say:

She used to like to listen to music . . .