I have learnt enabling is anything that robs another of a chance to learn something for themselves, and to be rewarded or to suffer the outsomes of their choices.
For example, my younger sister has two children, both of which my parents look after while she lives with her crazy husband. For the most part my mother spends 4 hours on public transport every Saturday taking her children to see her, despite the fact my sisiter has a car and my mother doesn't.
My father says it is nice for the kids to have a trip out which is probably true, but as long as my mother is taking the kids to her, she will never have to make the effort to see her kids.
While I can understand her kids need to see her, it is also not my parents job to play god and make this happen. It is my sisters responsibility to step up to the plate and make it happen.
I also think my mother taking the kids to her, robs her of the chance to build some kind of self esteem for herself. I.e. being responsible and going to see her kids would make her feel good about herself etc...
It would drive me mad having to unlock my parents house because my brother lost his key all the time, and to be honest I would probably 'lose' my own key too next time he asks.