I know your W was a bitch for taking your kids to another province, but I do still think that you could use a nicer tone. The sentence in bold sounds rude and bossy. Why not soften it a little? "My plan is to pick the kids up on 4/18 - let me know what time works best for you. I'd like to spend the week with them and bring them back to you on 4/25. Since you had them for Christmas, it would be reasonable for them to spend Easter with me." (Actually, I am not sure you need to say that at this point - the more reasoning you give, the more she can argue.)
(I don't know how much you have discussed already about the spring break week - has she already agreed to the week, or just a weekend, or nothing at all?)
The same thing with the phone calls. How about, "Thanks for letting me know about the new gymnastics schedule. I know the girls will love it! Since they will be busy during our usual phone time, would you please make sure they are available to talk with me at 4:00 instead?"
My Mom always told me, "you get more with honey than with vinegar."
It sounds like your W is being at least a bit more reasonable, so why not cut her a little slack?
me: 44 XH: 42 M 11 years D10 and S8 Bomb drop 9/27/13 D final 7/1/14
