It is never wrong to be kind, but there is kindness to be found in some acts that may seem harsh.
For instance:
When you always pick up toys for your child, you don’t allow them to learn to care for themselves.
When you feed your family only what they already love, you deny them the experience of new flavors and textures.
When you allow someone to treat you badly, to teach them that they can be cruel to people.
When you spoil your pets, you make it harder for anyone to care for them in your absence.
Being too kind is also bad for your own psyche.
When you carry each small burden for everyone else, you often find you don’t have time or energy to care for yourself.
The solution is to allow the people (and pets) you love to grow by being kind and firm.