I'm sorry another one is injured.
Getting hung on the board may be the issue. Any wire fencing where they may be scratching around and getting their feet caught? Fencing will cut that's for sure.
Another thought - would be some type of predator that's trying to get to them, but I find it...
Could be getting hung up in the sticks.
The wounds are almost straight across from one another it seems.
I'd just keep treating them with the triple antibiotic ointment, like you did the last one. Monitor the wounds closely.
Watch to see if she's picking at her feet or if another bird is picking at them during roosting.
If she's picking at her own feet, then give her a direct dose of Poultry Cell (1cc per 3lbs of weight) 3 times a week for a few weeks to see if that makes a difference.