Hi Dean,

I am truly sorry to hear about what you're going through.  *hugs*  I have a 10 yo lab who is at the tail end of the type of infection you're dealing with.  He's not the Tripawd in the family, but had a large fatty lump removed.  The lump itself was about the size of a pork roast - 2kg - and located where his back leg comes up to meet his body (front, not on his hip), a place where a lot of movement happens.  They stitched him up but the placement of the wound and the amount of fluid his body was producing in reaction to the surgery made it impossible for the stitching to stay in; the stitches came out about 2 days after he came home, so he had to have a very large, open wound for quite some time.  At the time the stitching came out, his insides were not fully healed, so he was actively bleeding/oozing for a while.  It took about 4 months for it to completely close, so I imagine Lucy's will close faster since it's smaller.  

Be prepared for a long haul and possibly some unexpected issues to arise in conjunction with the wound itself.  Here's some information for you based on things I experienced during my guy's recovery:

1) Be ready for a mess; you will need to change bandages probably more frequently than your vet tells you - nonstick absorbent pads and coban worked well but I had to get a full-body net to keep it all on him.  I had a "bandaging station" set up with everything laid out; I needed to be efficient with it because I was changing the bandages so frequently (~ 4 - 6 times a day).  If you can get some prescription shampoo from the vet that's for skin infections, I found this to be super helpful in cleaning up the ooze that crusted over his skin.  NOT the wound itself, but the oozy stuff will crust up all over and it's hard to get off of them.  I just spot cleaned him as needed to keep the area around the wound clean and you'll likely need to do this as well for the area around the drainage tube.

2) It's possible some of the stitching may come out and you will have to deal with that until it heals.  I say this just in case it happens.  They told me the stitching would stay, but it did not and that was a shock I'd hate for you to go through.  If this happens, don't hesitate to press the vet for as much information as possible.  If that happens and you're dealing with an open wound, it's a lot of work.  It is not, however, a bad thing.  As long as you can keep the wound clean, it's actually helpful for it to be open and heal from the inside out.  Counterintuitive, but there you have it.  My guy's wound was way bigger than a baseball, so Lucy will get through just fine!  It will just take time.

3) See if you can get some NeoPredef powder.  It's great for keeping oozing areas dry and is an antibiotic.  You can pretty much put as much as you want/need on for as long as you need to.  It works wonders, especially with skin infections/surface level stuff.

4) SUPER IMPORTANT:  Often times dogs will get a secondary skin infection as their bodies are trying to deal with healing a large wound like that.  It's not uncommon, but I was not informed of this.  The body can only handle so much, really.  Keep an eye on Lucy's skin and fur.  If she starts losing fur and/or you see alopecia with red scaly, peeling, oozing etc. skin, get her in asap to be treated for that.  She'll need a bunch of stuff to help her with that as well.  If her fur is thick, or if she has a double coat, check her over carefully.  It may take a while to present itself, also.  My guy lost huge amounts of hair, and even now that the infection is gone, he has large spots of brown skin that's healed but looks nasty, is shedding the dead, infected skin and a lot of hair is coming out (while the big alopecia spots are growing back in).  His skin infection was very deep and antibiotic resistant, so again, press the vet.  I'm not saying your vet isn't / wouldn't do an amazing job helping Lucy, but this can get real complicated real fast, and can be overwhelming for you.

He went through nearly the same process you describe...the hospitalizations, treatments, medical boarding, etc.  It's almost uncanny reading your post, to be honest.  But please know this.  A healthy ('cept for the bum knee) 10 yo lab at my house, although not fully furry (haha), is acting like a puppy again.  It is TOUGH to see a hearty dog out of commission like that for so long, but she will get better in time.

My best to you and Lucy!