Here's dosage from @casportpony.
The Silvadene is for the sole of her foot I presume as the side of her foot isn't open yet. That was where I more meant I'd use PRID was on the side to see if it pulls it out, but for the bottom, yes, I'd put Silvadene first, then PRID.
I'd consider the...
By the hole in the sole of her foot, it appears the vet did get the corn out, but must have left some in for it to spread like that. I honestly never heard of it spreading after removal and I've read tons of success stories of home treatment for bumblefoot.
I'd think she needs an antibiotic...