This is asked quietly and rarely out loud. The honest answer is that differential feeling between siblings is close to universal and says very little about anybody.
What is actually going on
Closeness moves. It follows whoever is easier to be around this month, whoever shares your interests, whoever is not currently thirteen. A parent who felt closer to one child at four often feels closer to the other at nine. It is a moving thing, not a verdict.
What children register
Not the feeling. Children are poor at reading how a parent feels and extremely good at counting. What lands is the arithmetic: who got asked first, who got the benefit of the doubt, whose version of the argument was believed, who is on the chart and who is not.
| Barely noticed | Counted precisely |
|---|---|
| Who you enjoy talking to more | Who was interrupted and who was heard out |
| Who you worry about more | Who got the consequence when it was both of them |
| Private feeling of any kind | Anything with a visible number attached to it |
The thing most likely to make it worse
A shared scoreboard. Two children on one chart turns an ordinary difference in temperament into a published ranking, and the slower one is not learning to try harder, they are learning where they come. This is the strongest argument for separate charts and it is not really about charts at all.
What repairs it is unglamorous. Time alone with each of them, on a schedule rather than when it occurs to you, and being carefully fair about the countable things while accepting that the uncountable ones will keep moving around.