Her birthday comment about d17 not to bother coming strikes me as a pity party looking for sympathy/pity/some emotional response that she no longer should get from a "fired H".
Other aspects of this also indicate she is attention seeking. Stand firm. Do not rush in to make her feel better. She made thus mess, she needs to figure it out. Give her the time and space she needs.
You made a decision based on what was best for your daughters.TThat was a good decision.In the future avoid lying/even white lying. Firstly there is no need and secondly she could turn lies against you. If you don't want to tell her your plans, don't. But avoid telling her mis-truths.
Although disagreeable to be on the receiving end, IMO anger is not necessarily a bad sign. It is way better than indifference. Validate as much as possible but just as importantly do not let her talk to you in an unacceptable way. You seemed to do that just fine.
When attacked it is normal to fight back. Control that urge. Don't be walked over but don't add fuel to that fire either. Normally it burns itself out quicker if left alone. She accused you of manipulating your girls. From everything you have written it is obvious you are not. You know this to be true. You do not need to convince her. In fact maybe you couldn't ever confince her at the moment. So it is a waste of time and effort to even try.AAs I said you know the truth. Let that be enough.
If anyone is manipulating your kids it is WAW. Do not ho on the attack over that. It would be so easy to do so. It will only add to the conflict and further convince her of how you are against her. The battle will only escalate into a full out war. That is in no ones interest. As long as daughters are not being hurt, let it slide. Be prepared to step up if they need protection.
You are letting her make you rethink every move. That is within your power to change.Take that power back. Do not let her reactions determine your decisions. Decide what is best each decision and leave it at that. Easy words to write but harder to do. I know that, but I also know you can do it.
Best wishes.
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together