I noticed you asked a few questions and there were a few very important points that were not brought up that may prove to be useful knowledge, just as future reference.
You asked if it was "OK" that the dogs tied so many times the answer is NO! It is very dangerous for dogs to be allowed to free breed and more specifically to tie without close, hands on human supervision. This female (and male) could have suffered injuries as a result--time will tell, hopefully all will be OK. It would not be unheard of for the female to deliver prematurely and lose the litter--semi-common when a bitch has been overbred. Just something to be aware of "in case" so you are not caught off guard.
For the record, no one here has claimed to be perfect and no one has talked down to you. The situation is the result of
your brother's actions,
not yours.
You are trying to make sure that the best interests of the girl are being met. No one is placing blame on you, please don't think that. You are understandably frustrated with the situation, but please try not to lash out at those trying to help you. Sorry to say, your brother is likely a very noble, stand up guy--but regardless to what excuses can be offered in his defense, as a pet owner, he has acted very irresponsibly
and his dogs, the female in particular are paying the price.