OP, My original reaction to your post came off a bit harsh, and I am sorry for posting so soon after reading the responses as well, I should have thought of a more kind way of wording my post, you're right.
I do sincerely hope that you can find a way of handling this puppy and getting help with her training so that everyone, including the puppy, is as happy and able to learn how to deal with each other, given the circumstances that you have to work within. I really never meant my response as any sort of attack on you or your abilities to have a pet. I just honestly KNOW from experience, that out large breed active dog took so many years of constant training (daily and nightly) and dealing with her in ways that were not always easy for us... but we knew would help her to be a trusting, loving, protective dog in the end, which she was... but it definitely took quite a LOT of patience and sometimes going against our nerves, for certain!
Dogs don't always play the role of cute and nice and they take a lot of time to train how to just "be" part of this human oriented race and household that we expect them to naturally be, and its not an easy path at all, for us or the dogs. I did not even have kids at the time our pup was learning, and I worked from home so I could be on her whenever she needed to learn some new way of dealing with her puppy frustrations... thats why I think crate training can sometimes backfire on people... b'c the dogs don't really learn ways of dealing, they just learn fear based responses. But, I also acknowledge that crate training is a whole other field of belief, and thats ok, it just never made complete sense, from the animal's perspective, to us. We were wanting a puppy for two years *very strongly* before even getting one.
I truly was only trying to give you support, as I know from experience that its NOT an easy road to train a dog into being a well behaved family pet, and that they can and typically will, put you to the test daily for a few years. Especially large breeds. Since you are only about 8 weeks into this and were already feeling frustrated and had suffered a few scary incidents for you, I thought I'd give support in saying that rehoming is not an evil thing to do. I hope you can find the support that you need... I've been feeling terrible since I posted, for my immediate response in protection of your dog, as it comes across as judgemental... I know that you have a big heart and want the best for everyone in your family, including this puppy. Its clear that you love her too.
Plus, unlike another pp said and seemed to read into my thoughts, I do NOT feel that your kids come 2nd by any means, just that, if the puppy can't get all that she also very much NEEDS as far as her own growth and confidence training right now, b'c of course you need to see after your kid's safety first (absolutely!), that maybe think of rehoming her before she gets too much older and would be unable to be re-homed safely for her own future good.
Please know that I did have all of your family's safety and peace in mind, even if my first post comes across as only caring about the dog and also tagging you for any personal weakness as far as owning/training a pet... I do not feel that way in the slightest. I just could not imagine trying to "superwoman" it all on my own, from what you posted that you have going on right now. I really do wish you the best and the best for the puppy as well. Sorry if I made you feel bad at all, not what I meant to do.