You have put Nova through massive changes, plus she has massive hormone changes. It's no unusual at all for intact bitches to fight, get territorial, etc.

IMO, far better to crate for a couple of months until things settle down than have an actual fight from which their relationship may never recover. Yes, keep the crate in your room at night, but give her yummy treats, a special toy etc so she does not see it as being punished. Talk pleasantly to her, up voice "crate time" and work on being calm with her. Exercise her a lot.

When this is over, work a LOT on socialization. Biting is a quick route to being sued and dog put down. If she will bite your little sister, she is liable to seriously bite a stranger.

Work a lot on obedience... learning down/stay (I can tell Moose, our Samoyed, "timeout" from anywhere in the house and he immediately comes to lie next to me or even under my chair.), leave it, etc are critical.
http://www.clickerlessons.com/index.htm

Welcome! We flew our basenji and samoyed from the USA to Israel..no problems.

Spay/neuter or leave intact, and when, ... all the data isn't in. I think you need to really read the research and make your own decisions. But I certainly would wait until 2 or 3 or not at all. And realize even then, both can have deadly consequences. IOW, it's your dog and choice as you'll be the one carrying the loss if it goes bad.

My big concern for long cycles is pyometra. The longer the cervix is open, the long bacteria has to enter and cause an infection.

Have you talked to your breeder? Seems like she should have told you. Call and ask.
r

Absolutely!

@tanza
While I agree that is almost always true, it is not absolutely. You can say "must not know where the sickness is"... but I have personally know known of a dozen for whom no medical issues were found that WOULD hold out until skeletal.

Please check the Basenji Club breeder's list:
https://www.basenji.org/index.php/about-basenjis/breeder-directory

Sadly, most isn't exaggerating... it is fairly realistic preparation. If you need an easy dog, a dog that is easy to train, on that won't challenge you or look for alternate ways to do what you said literally without actually complying, this isn't the dog for you.

The upside: Waking up to sayblee's nose gently touching mine to wake me up. The "not dog" smell. They eye contact and feeling of companionship more than a pet. Watching the cogs turn as they figure things out. Gaining their trust and love so they are willing to work with you.

Consider fostering one for a few weeks up to 2 mons and get a close person view of what it is like.

There is NO BREED OF DOG ON EARTH that is hypoallergenic. Period.

I totally disagree with "keep the dog outside" but the rest may help. Try being around the dog or several. See how you can tolerate it.
https://www.mayoclinic.org/diseases-conditions/pet-allergy/expert-answers/hypoallergenic-dog-breeds/faq-20058425

Cancer in the bone can spread fast. Get 2nd specialist attention asap and go with recommendations. Dog might be fine, but waiting might mean death. Get expert infi and adt

NONE of that erases that breeding to make money is something you pointed out as a legit reason to wait. Please stop.