You probably already have quite a bit of experience with this condition if your 7 month old daughter had cataract surgery when she was 2 months old.
There are many permutations and combinations, but the scenario in your particular case is that of cataract in one eye in a child.
In this scenario, if the cataract is very dense, then not doing the surgery risks making the eye very lazy (amblyopic).
Doing the surgery does not make things perfect, but at least the cataract is not blocking the child's vision.
In other words, even with perfect surgery and perfect recovery, it is rare for the operated eye to be as good as the other eye which did not have a cataract.
There are many aspects to 'recovery' after cataract surgery in a child.
The wounds themselves heal very quickly, often in less than a month.
Often, children less than 1 year old do not get a lens implant, in which case, the child would need to be fitted with a contact lens.
This contact lens gives clear vision at one distance, but not other distances.
This is very different from the other, normal eye.
So the operated eye is always at a disadvantage and always at risk of having lazy eye/amblyopia even after surgery.
In order to avoid this, the good eye needs to be patched for a certain time period each day, to make sure the child uses the other operated eye to see things as well and so reducing the tendency for lazy eye/amblyopia. This patching most likely needs to be done to some extent throughout early childhood.
If no lens was implanted, a contact lens may be worn for the person's entire life. In some cases, they may elect to have a secondary lens implanted when they are much older, perhaps in adulthood.