Yes that's bumble foot, give it a good wash to make sure, while being gentle.
Treatment:
Read up about doing the surgery. That's if you are confident about doing it yourself, if not take her too the vet if possible. For the surgery I would recommend tweezers and cotton wool to mop up any blood that may come out. The infection is white and stringy usually, you want to try to get this and the kernel out.
Before the procedure do an Epson salt soak for at least 10 minutes (warm water). To soften the scab. For following days treatment re - rap every 24 hours. Complete an Epson salts soak for 10 minutes and a 1% beta-dine solution towel soak for at least 20 minutes. Before applying tipple antibiotic cream to a small square of gauze, put that on top and rap with vet rap. Keep this up until the new scab drops off, the new scab should be a light brown colour.