pregnant stray

Question
I have a dilema here.

There is this little white dog (looks like a JR terrier mix) that has always come by my house.  I have a 3 YO male great dane.  I have shipped my dog to my moms house back in January but this little dog comes and visits every now and then.  She has a purple collar on, so I thought it may be someones?  But the collar started cutting into her neck and I personally made the collar larger so she could breathe.  I have been away from home for almost a month.  Today this little dog came to visit and she is HUGE.  She has defnitely gotten pregnant by some other dog!  I am assuming that she is stray, but not quite sure, as she leaves my house every night.  She looks like she is due at any time.  I do not know if I should contact the animal shelter or if I should just keep her here at my home to give birth to the puppies.  I do not want the puppies to be hurt in anyway.  Nor do I want to keep someone elses dog!  I am also worried about her bringing in parasites into my home that my dog can potentially get.  I do not know what to do!!  I have always had male dogs, so I have not the slightest clue when it comes to whelping puppies!

Answer
do not give her to the shelter, no matter what they tell you to your face, they will put her down.  Ihave heard of this many times.  Try and find a local humane society.  They will probably take her.  If not, I would take her in. Before you do, put some advantage on her and get a capstar from the vet. This will not hurt the pups.  If you do that no fleas or ticks will invade your house.   If  you keep her for a few days, the owners may show up.  She should pretty much take care of having the pups herself and I can help you with anything on that score as long as she is doing ok.  
nancy