personally, and i'm not trying to be mean, i wouldn't do it simply because of this. it's males. you just had to rehome your GSP (that's the right breed right?) because your other two boys were attacking him. i would think really hard and long about having another, larger, male in the house. she's a breeder so chances are they are either not fixed or just got fixed, but regardless you'll have more testosterone in the house, and they'll still "smell" like unneutered males. what happens if something happens to that dog, and it gets seriously hurt by your two boys, or worst yet, what happens if your boys get seriously hurt. then, you also have a daughter (i'm sorry, i don't know how many kids you have) that will be in the middle of all of this. what happens if she gets bit b/c she accidentally gets in the middle of them. can you separate the dogs 100% if need be? while, yes, it would be very nice of you to save these animals, maybe you could tell her you'll be a last resort? this way other people who would be a better fit to have them permanently in their house would have a chance to get them, but you could get them if it was 100% for sure that they'd be PTS. hope you don't think i'm being rude, but that's my opinion.