A lot of the OP's "odd" behaviour could be explained by being totally emotionally broken by an abusive partner.
Have had experience with emotionally browbeaten and neglected, frightened children. A common behaviour there was to keep repeating what they thought the other person wanted to hear to gain support, affection and approval.
Especially if that person was someone who was sometimes kind/supportive/loving and sometimes not. It's a desperate attempt to get on the "right" side of that person. It shows deep fear, insecurity, a desperate need for some kindness and acceptance.
Agree with PP who have mentioned how many attempts it takes a DV victim to leave, that she is scared and brainwashed and a shadow of a fully functioning person.
I've just RTFT and the past one. So, maybe this isn't real, maybe it is frustrating. But this is an internet forum, that's totally possible about anything you read on here. Not seeing how being browbeaten and repeatedly questionedis going to help someone who is already being browbeaten and emotionally broken though.
Re the dog, a (gay, male) friend of mine was bought 3 kittens by his partner, to cement a failing relationship. As relationship continued to fail, the partner turned (emotionally and physically) abusive, and one of his tricks was to threaten the pets, precisely to keep my friend in line, without having to raise a hand (although he raised a hand plenty other times). So this could be something the partner is deliberately and repeatedly holding over the OP. (The friend managed to escape when a former partner offered a safe place to live, his only real family had died. It took a lot of time and support to get him to do that, he only did it because he felt his former partner was someone he could trust physically and emotionally, so he wasn't jumping from the frying pan to the fire).
And yes, she could also be using the dog as an excuse not to leave, but it's just a mask for deep, deep fear and terror that she isn't strong enough to overcome yet, nothing else. The dog is an ostensible reason, doesn't mean there isn't a real one hiding behind it.
Her partner could be making (very real) threats regarding the OPs family. She could feel very trapped- if she goes to a refuge, he will turn on her parents/their children. It could feel like some horrible catch 22- can't take kids into safety of a refuge til she gets them back, can't get her kids back til she leaves him, can only leave him by going to refuge as no room at parent's.
So he is effectively holding her hostage by making threats to her parents and kids- she can get herself somewhere safe, but that will exposing her parent's kids, or she can think of her parents/kids and continue to expose herself to that danger. Being caught in the horns of that dilemma is another trigger for repetitive thinking. And again, it shows how manipulative and controlling he is to do that, how much of a hold he has on her. For all we know, he could be, as a PP's sister's partner was, someone who really is very dangerous.
He is also using shame as a very effective jailer for her. Maybe some of his controlling ways involve telling her how no-one will believe her, that she'll bring shame on her family, that people will just use her as a target if she is open about it etc. It is so pernicious and destructive. And when she is open about it on here, if people get frustrated and angry with her, it will (inadvertently) re-inforce what he has said to her- that is she is open about this, no-one will believe her and they will be horrible to her.
Shame could also be what keeps her from disclosing why she doesn't have her kids, and the attitudes she is experiencing from some posts are hardy likely to make her more likely to open up about it. It could be that he abused the kids, that SS suspect he abuses her too, that's why she cannot have them back whilst she is with him, that her parents do know he abuses her but are waiting for her to raise it. I'll repeat that again for the OP- YOUR PARENTS ALREADY KNOW, THEY ARE WAITING FOR YOU TO TELL THEM.
And the repetition could be a mantra- if she just keeps saying it over and over, some way out will come to her. People often go over things again and again and again when very distressed, especially if they feel impotent. Or, she will start to believe it and will find the strength to do it.
The OP could be so far into being controlled and emotionally broken that it is a huge thing for her to post on here, or chat to Women's Aid. It's a little green shoot that needs slow nurturing not scorn and ridicule, for an abusive partner will give her plenty of that already.
So, it's not beyond the realms of possibility that the OP has come here many times for support and kindness, to help build her confidence, get a chink of light in her life and build something inside herself that will help her leave eventually. But when people get frustrated and upset with her it sends her in a spin. She could just be looking for safety and acceptance to help her gather the strength to do what she needs to do. That needs to be consistently forthcoming if it is going to do any good, whatever the timescale.
Yes, this could be a hoax that wastes some time on the internet. Or it could be real and the person at the other side of the screen is someone who needs a lot of nurturing and coaxing to even be able to begin to find her own feet.
I think most people on Mumsnet know that the social support system isn't perfect, and that some people do really get caught between a rock and a hard place. Yes, help is there, but it's not comprehensive, it's not universally forthcoming or properly joined up. Most of all, it might take the OP time to trust that help, trust it enough to make the leap.
Just being a supportive voice might help the OP. Even if it takes a while.
So, OP, I hope that you do find help. I hope that you do find the courage to leave. I hope that you do build a new life and get your kids back. I know it can be difficult, I know it can be hard. Your are taking your first steps. Stay on that road, go as fast as you can. You will manage.