Alright,.since it sounds like you only have one pair of hands, I'd actually start at the window. I'd work on Look At That training for the girl, but, in the moment before your boy gets wound up--reward the quiet. So it'll look something like this: Girl rushes over to bark and boy looks up. You toss a treat at boy before he gets wound up and mark/verbal reward. Girl likely gets distracted by this, you snag the moment and switch to LAT with her. Doing this inside helps build a foundation.
Sounds like you might have a balcony? When you and crew are ready for the next step, step out onto the balcony and repeat the procedure. Then in the car or in a parking lot--distance is you friend. Then the hallway. By doing this, you are generalizing, practicing good behavior, and building foundations. But also setting yourself up for growth.
Simultaneously,.I'd start charging an interrupter. It can be any odd noise, like pspsp for cats--the point is to attract attention. I'd build by making the noise whenever I'd feed them/place their bowls and randomly paired with a treat. The goal at first is to build an association and tension that tuning into this noise=good things, worthy of attention. Once that's been established, for example if the dogs are lounging in a room away from you, you make the noise and they come the minute they hear it, you're ready to incorporate it.
This would look something like: you're on a walk, see dog in the distance. Your dogs are looking but not barking, lunging, etc.; you make the noise, they look at you, you treat and change direction or practice basic manners. When they look back, the other dog is usually gone by then. And, oh lookie!
Not barking and lunging can
also make the other dog go away!
By while you are laying foundations, I'd recommend walking them separately like
@CachetheBC says so they are not practicing the behavior and setting your progress back.