if she is panting she very well might be in labor. You should have her in a room by herself no other dogs theyre a threat in her mind and she will defend if feeling threatened. YOU WANT YOUR MOM CALM!
I also suggest a cage is not where you want her to whelp. You want to have the ability to access her or the babies if she needs your assistance. Have a heating pad wraped in a towel for the babies as they're born if they get chilled they can die. Gosh there is so much to explain and very little time for you to understand.
If youve never whelped you need to look for signs of labor please read this site it will be helpful...but first and foremost have your vets number ready and your car keys handy...If you dont understand what your doing you could jeapordize your moms life and her new babies, then you need to make a decision to have the vet help you.
http://www.debbiejensen.com/whelping.html http://www.debbiejensen.com/normal_whelp.html http://www.debbiejensen.com/livebirth.html
hope this helps