Got a reply already. Here's an extract I'd like advice about. The rest is OK.

This half term has been taken up partly with revision sessions. I took the boys away for one night to Suffolk. Not wishing to quibble, technically last weekend was not "your time". We added it in as extra for your birthday, remember? Had you wanted more time with the children over half term you just needed to say so. And that applies at any other time too.

Not wishing to quibble? Looks like this is a quibble to me.

In advance of my birthday and S12's coming up, I realised I wouldn't be there for either, so I changed weeks. So as far as I'm concerned, this was not an extra. In addition to this, she conveniently forgets that I only see them every other weekend, while she has them all the time.

Should I make this clear or let it ride?

M: 57 / EW: 52
T: 21, M: 8
S: 18, S: 15
Bomb: 1 Jun 14
EA Aug 2014 I think
PA Feb 2015 possibly sooner