Jennifer Bonjean said Kelly recently had surgery on his Achilles tendon after it was discovered last week he was suffering from blood clots.
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Bonjean said that's due to negligent care provided by the Bureau of Prisons.
"It's not just because it's R. Kelly. Every prison deserves medical attention, medical care," she said. "The MCC is required to address these things in a competent fashion."
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ABC7 reached out to the Bureau of Prisons for comment, but has not heard back.
Kelly is currently serving a more than 20-year prison sentence for sex crime convictions in Chicago and New York.