There isn't a blanket reason why it wouldn't be. In a particular case it's up to the judge, and the judge's decision probably depends on the quality of the experts that can be found to explain it.

I am not a lawyer but it would seem if you attest to the fact that it is reliable data it would be admissible. Lying under oath and fabricating evidence is still against the law.

> To disprove her allegations I wasn't involved in the kids school and activities...

There don't seem to be any criminal charges here.

That doesn't mean you don't get sworn.