Here is my .02

Take it with a grain of salt as its just my not so humble opinion

I feel your pain. I really do. I just recently broke up with a man who I didn't think was a good influence for my child. Even though my baby is only 14 months old.. i am not willing to sacrifice his experience growing up for a man. There are always other men(or women in your case) in the sea.. who may be more suitable for you.
Personally.. I think that both of you are just not happy with the way things are going. She feels she is not getting enough of you, and you feel that she is asking for more than you can give. That shows that your relationship priorities are very different. Can I ask - When you started this relationship, were you clear about what you both wanted?(I think thats basically what you stated, but I just want to be clear for a few reasons)Personally, if you entered the relationship with certain boundaries, I feel it is unfair for her to become bitter or passive-agressive about those boundaries later on. Much as it would be unfair to agree to no children, and then later on one decides that they will demand children.
Your children are your children, and they are tantamount here. In the end, like i said, there will always be more people to meet, but you only have the children you have now - you can't just go and replace children. If you truly feel that her children are going to be a poor influence to yours, then you are absolutely bounded by the responsibilty to protect your children. And really, her parenting is not something you can really have a say in as you are not their step parent and it is not your responsibility or privledge to parent them. You can make suggestions in care, but even that can put her off if not worded correctly.. its a very sensitive issue.
It sounds though, that you have a healthy amount of love for this woman. You strive to make a life with her, as much as possible, even though it requires many sacrifices and much planning. She doesn't seem to have much appreciation for this in my eyes. Im not sure why, if I was in her position id be pretty damned happy that you were making all of those adjustments for her, even though i might be a tad sad i couldnt have more.. i would know what i got into in the first place.
I wonder - because you will not let the children mingle - do you think that perhaps she "understands" why, but feels a little bit angry because of it? Maybe she feels a little judged? I am just thinking of how I might feel. Keep in mind I WHOLLY agree with your decision.. but i know that might sting a little bit as a mom.
I wonder too if maybe she is starting to tire a bit of all the run-around required for you to see each other? And it sounds like maybe you are as well, if not conciously than subconciously.
I dont get why she was unhappy with a new camper. Well, i guess I can see being a tad unhappy with not being involved..but not to that degree. I sort of feel that she might be choosing her battles in a way..if you know what i mean. OF course there is ALWAYS two sides to the story so im sure there is more too it like you say. Personally speaking. im sure i would be a LITTLE miffed at not being involved, but id be really excited to see a new camper. From what you say it sounds bigger/better than the old one? That cant be a bad thing.
I am not sure without knowing her if going to the bar is a bad thing or not. It really depends on her personality and if she is the type who cannot control herself when drinking or who tends to drink to excess. Personally the not remembering would worry me, not just because it may lead her to infidelity. Personally i think thats the least scary thing that could happen. As someone who has been Roofied twice at a bar, and thank GOODNESS i had good friends with me who spotted it and basically swooped in to save me, it is VERY dangerous to drink to that excess and leave yourself vulnerable. Not just that, but she could end up saying the wrong thing to the wrong woman and end up the victim of violence, robbery or any number of things. Bars on a whole are not where the most moral of people hang out, and a bunch of drunks is usually bad news. Does she go with friends or alone? This to me would make a big difference.
Now, heres some positive stuff!
There is totally room here for you to try and make it work. I think you need to sit her down and have a very serious conversation about what you both want, need and desire out of this relationship. You need to be COMPLETELY honest, even if you fear a negative reaction. Truthfully, if you get a seriously negative reaction then honestly you probably should get out and move on. In my opinion everything and anything can be worked out if both parties give it their best and agree to comprimise.. some people cant do that. I would start by telling her exactly how you feel about her, how important to you she is. Make sure you talk her up before you start the conversation and continue to drop the odd reference to your love for her throughout. This will lessen the feeling of it being an attack on her, as she seems terribly defensive. I strongly feel however you need to get all of this out in the open and talked about before it festers some real resentment on both of your parts(more on hers from the sound of things but like you and i said, two sides to every story).Yes, this may be the beginning of the end, I cant promise you that it wont be. But i think that unless you want to stay in a relationship where you are treated as she is treating you(which is disrespectful in my eyes at the very least) you need to adress it. I think though you also probably knew this all along in your heart.
I wish nothing but the very best for you, and will keep my eye on this thread. If i can think of anything else Ill add it!