if the operation will help than I don't see why not.
If I understand correctly, her Falopian tubes are blocked. The fallopian tube is what attaches to the ovaries and carries the egg into the womb when she ovulates. If the fallopian tube is blocked then the egg isnt traveling into the womb and there is a very low chance that she will be able to get pregnant.
I asume that what the doctor said is that they need to operate to unblock her tubes so she can get pregnant later on.
I'd say, yes if you both want to have a baby it is a good idea for her to have this surgery.