Awww... 60 Kg. (132 lbs.) is not all that heavy for a more mature "lady", right?
Try the 42 cm fin.
Depending on your sail size, you will perhaps want to switch back and forth between the 42 and 48.
If you are well powered up.... use the 42 cm.
If you are having a hard time getting planing.... use the 48 cm.
Either fin will be "easy to handle and control" if you choose the fin that suits the conditions and sail size.
Hope this helps,