I've rescued many dogs and cats, and never had a problem brining in new dogs into the pack overall, especially girls. Although girls can certainly fight just as much as male dogs in some cases.
They'll have to get used to each other so it's not really the immediate reactions to be concerned about, you wouldn't have reasons for concern unless they have either a longterm problem, or you're bringing in a new small dog who could get injured easily by the other, which doesn't seem to be the case. I have a boxer mix, they're good dogs to, save her.
God bless!