The Borax really works. You have to sprinkle it everywhere the dog has been - carpet, furniture, blankets, even your car if she's been in there. Let it sit for at least a few hours, then vacuum it up with a flea collar in your vacuum bag and then throw away your vacuum bag in a zip lock baggie. Do this every single day until you notice the fleas are gone. Many years ago our dog, who had never had a single flea, got infested when we moved from Colorado to south Florida. She had to be flea dipped twice and they had to shave her (she was part Collie so you can imagine how much hair they had to remove!). I paid a guy almost $200 to do a flea treatment of the house - come to find out he used Borax! I could have done that myself! It's not harmful to you or your pet as the flea sprays and bombs are, but granted it is a lot of work to sprinkle, wait, and vacuum every day. SO worth it though!
We use Trifexis on our current dog year-round, and we have the yard sprayed for fleas monthly, too.
Good luck - fleas can be such a horrible hassle to deal with.