Background: Have joint custody of 3 kids. Week with me, then week with their mom. When they with me, their mom has zero to do with them.

Last week all three were ill and off school. That day there was a hearing test at school

Their mom then contacts me, wants to know what happens now that the hearing test has been missed. I emailed the teacher, didn't get a reply.

Kids went back to her at weekend. Out of the blue I get this message:

Her: Did u bother to find out about the hearing test?

Me : Did not get a reply

Her : So didn’t bother to try to find out?

Her: I have called the school many times to find out

Well

Since you aren’t asking as u aren’t interested…, I shall I tell you.

They don’t offer it again.

So you missed it totally

Am I overreacting or is she deliberately trying to make out that I fucked up?

The whole "did you bother" and "you missed it totally" are unnecessary, I would never write a message like that to her.

I am ignoring her now, but boils my blood that she would dare make out that I somehow fucked up.