Undiagnosed or No Diagnosis to make?

So baby is 12 weeks old. At 12 weeks with Tiddler we had only just about left hospital, she was behind in development already and things were very uncertain.

This time round, Baby is developing normally we think, although I will admit to a niggling worry about her tone. her arms, particularly the left, is very rigid- the exact opposite to Tiddler, she sometimes lets out a cry when we lift her out of a chair. Also, she still has head lag from being lifted from the floor. It took Tiddler about 12 months to lose this, and it was always commented upon as being unusual. That baby also seems to have this is worrying me. Does this suggest a link, a genetic problem they share?

This may appear hysterical or disproportionate but just as with an undiagnosed child you spend the whole time wondering if *that* symptom or quirk is *the* missing piece to the Tiddler jigsaw, so I find myself wondering if similar physical attributes or features point to a genetic wobble that the siblings share.

Despite everyone telling me, and me believing most of the time, that things are different with Tiddlers little sister, I can't quite believe that this is the case. How can two children be different like this? Of course, this is a stupid thing to say, you can have very different siblings, but I suppose because there is no explanation for the way Tiddlers start in life went, I cannot rationalise that the two are so different as to not share the same problems. If there is no genetic issue, then why has it all happened to Tiddler in isolation??

I suppose it all goes back to our need to explain and find a reason for everything. Scientific advances have encouraged us to believe that nearly all questions have answers, so when one finds a question without an answer we struggle. We no longer attribute things we don't understand to fate or God, we want reasoned answers for everything. Of course, not everyone finds their answers and so are left lacking and searching rather than living in the moment.