Could you correct or confirm if my definition fits with the example given?

Hi teachers,
Could you correct or confirm if my definition fits with the example given?
a) The frequency expression and the past time marker, inform on the frequency with which Sharon phoned Robert at indefinite points of time in the past, and when she did it.

Sharon studied Spanish every week last month.

Will it be better this one?
b) The frequency expression and the past time marker, inform on the frequency with which Sharon phoned Robert in the past, and when she did it.

Thanks in advance.