From the Husky point of view when around 9mths hit, that is usually the age where they will push at boundaries and suddenly exhert their independence.
Up until then people often think they have got a sibe thats an exception to the normal as some can be quite dependant and even stay with them when let off. They do play rough too and use their mouths a lot in play, even with each other. As another spitz more natural breed I should imagine the Akita plays the same, roughly. The Sibes are usually very clear with their body language and signalling , where as, I have heard that Akitas especially the American type dont give much away regarding facial and body language expressions.

I would cease all rough housing play straight away, it will only encourage it.
That means especially OH. I notice that you say your son is nervous around her? If he is nervous and unconfident that will reflect in his body language and movements. Is he stiff and tense around her? If he goes to stroke her, is it what I call the hesitant shall I shant I hand movements back and forth? If he does this, then it will likely hype the dog up, especially the back and forth hand movements, it almost makes the hands an interesting target with the movement. If he does this calmness around her is key.
They will also mouth and nip more when they are excited, in fact excitement often starts it off.

As already said no more rough hosing games. Instead substitute it for structured play and training sessions. Using treats and praise initially to get her to sit, down wait etc. later you tailor them off anyway when she knows the commands and it becomes a conditioned response. Use the "obdience" in structured play. You will need to break it own as training exercises first and learn each part so its solid. Start with a reliable sit. Then a sit wait. Then work to throwing a ball whilst keeping her in the sit wait. Then teach her Find it to go and get it. Then encourange her to pick up and bring it back. Then teach her drop to give it up, then Sit wait again for the next throw. Once each part is learned then you can put the whole thing together. A good way of structured play, a sneaky way of teaching loads of commands and practising them in one. The dog doesnt even realise its training, and most importantly the dog learns impulse control, joy also with the physical and mental concentration it wears them out.
Keep her mouth and mind busy too on things like Kongs, Solid hard rubber you can fill with wet food from her allowance or all manner of things see Link, especially section how to Kong. Dog & Cat Toys & Dog Treats - Pet Toys, Dog Chew Toys | KONG Company

Treat balls are good too, you fill them with kibble and set to distribute some here and there as they play here is an example but there are lots
Buster Cube - Home

Have a good supply of Dog chews too Stag Bars are a good one as well as all the usual suspects chew wise Pure Dog | Stagbar antler dog chews | natural dog treats | organic dog snacks | hypoallergenic dog chews | long-lasting dog chews | teeth cleaning dog chews | low fat dog treats
If your son has mates round and they want to play active and noisy games that will likely hype her up, if he wants to play give her some wind down time with one of the suggestions to keep her occupied.

I would also say consider her exercise levels, dont know how much shes getting? but they need regular exercise. If she is not getting enough that will make her more hyper and mouthy, a tired exercised dog will be calmer and settle easier.

Try to establish a routine, with regular adequate exercise, plenty of short but daily training sessions, 2 or 3 15 minute sessions mixed with play can help, Sibes dont do long repetitive boring training anyway usually. Cut out the wild
roughouse human/dog games. Sibstitute for calmer structured play. use the Kongs, treatballs and chews, and Im willing to bet you see a difference. Also yes its something that does get better with age. However, control and routine does need to be put in place too.

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A: No.

many people may tell U to smack a disobedient child, but that's not highly effective in most cases,
& is moreover likely to estrange relations between the child & parent.

in a dog who is ALREADY BITING, 'tapping' their nose will only escalate the intensity of bites, most-likely,
as the dog will feel defensive - OR it may stop the "nipping" but replace it with FULL-FORCE bites.

the dog just recently arrived, has no reason to utterly trust anyone, & is feeling unsure already -
adding more worry to an already-stressed animal is a bad idea, IMO.

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terry pride, APDT-Aus, apdt#1827, CVA, TDF
*wolves R wolves, dogs R dogs, + primates R us.*
tmp, sept-2007