Thanks for the additional information. It is actually very helpful.
It is an adult dog's job to teach pups how they are supposed to act around adult dogs. A mom generally gives her pups a lot of leeway and allows them to nip her face, jump all over her and generally be very disruptive. Even adult dogs allow very young pups to do things that no adult dog would tolerate from another adult dog.
Your new pup is no longer a young pup and the behavior she could get away with when younger will not be allowed with her maturing into an adult. At 5 months, it is only a few more months if that before she goes into heat and is sexually mature. So your lab/chow is likely making sure she understands what is acceptable behavior and what is no longer acceptable. Growling is more than normal. I'd even expect him to lunge at her and possibly even nip her at one point or another if she fails to curb any unacceptable behavior such as ambushing him, eating his food or nipping at him. As long as he isn't drawing blood, I'd try my best to let them work it out.
If you want to take a positve role, you can keep a leash on her and do the reprimands yourself. If she starts bouncing at him, or running straight at him, intercede and stop the behavior using the leash and a firm low toned NO. I'd go ahead and start obedience training the pup now as you are getting a late start if the pup is already 5 months.
The following site is helpful in helping owners train their dog. Be sure and click on the link to the page on obedience at the bottom. and links on subsequent pages leading to detailed instructions.
Training works best if you train at least 30 minutes a day (two 15 minute sessions). I would start making your dog work via the Nothing in life is free program (NILF). It is outlined below.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer positively so I am compensated for my time.