Most parents try to always be fair to all their offspring, but sometimes one child, by his or her very nature, may need more attention and effort than other children. This requires developing patience, coping skills and an acute sense of humor.

It is OK to treat your children differently, according to their personalities, learning styles and emotional stability. It doesn't mean you don't love them equally.
Giving attention as needed is a natural and normal process in parenting. This is different from favoring one child over the other. As parents, you know how much attention you give to your children.
Whether you're aware of it or not, however, the kids keep track of how much attention, both good and bad, they get. And they compare it to their siblings. They often will give hints when they feel the attention is imbalanced. Don't be swayed by your guilt; it's part of the process.
It helps to set aside times to be with the child who doesn't require as much from you. Make dates and try not to break them; if you must, make sure you give a good reason and make it up to them.
(Source: redding.com