I am guessing your vet did not prepare you for what may come next.
prepare yourself for a most gruesome sight in the next few day. it will most likely burst open soon and she will have a huge oozing hole on her breast. when that happens, don't freak out. it is just part of the healing process. just keep it clean and it should close up pretty quickly.
The essence of hypocrisy is the tendency to make an exception of oneself.
I have had to deal with this before. Put a hand towel in very warm water and put them on her teets. If it has not blown out you can milk out the infection. As you milk her you will see slimmy milk come out try to get as much out as you can. Do this every couple hours till it is running clear and the knot is gone. If you have a blow out you have to get a bottle with a tip you can swert sterale water out of and rinse it out that way. How old are your puppies. If they are over 4 weeks get them off her and on food. If not try to cover the nipple that is bad for a day or so till the meds and your milking starts to work.