The honest answer is that it is unlikely, and going in with realistic expectations will save you a lot of frustration.
Federal inmates are required to serve at least 85% of their sentence barring exceptional circumstances. With a 30-month sentence and a release date of January 2024, she is already on a relatively compressed timeline. If she keeps a clean record, no incident reports, she will serve that 85% and get out on schedule.
Compassionate release exists on paper, but the Bureau of Prisons has a poor track record of actually granting it. Even inmates with terminal diagnoses have been denied or had requests drag on so long they died waiting. Diabetes and general health problems, while serious, typically do not meet the threshold the BOP uses to act. FMC Carswell is a federal medical center, which means it is specifically designed to house inmates with medical needs. The government's position is that she is in the right place to receive care, and that argument works against a compassionate release claim.
The one wildcard that emerged in recent years was COVID-related home confinement. During the height of the pandemic, the BOP did release medically vulnerable inmates at a higher rate. If conditions change significantly, that avenue could reopen, but it is not something to count on right now.
What she can control is her conduct record. Zero incident reports, participation in programming, and good behavior keep all her options open and ensure she hits that release date without complications.
FMC Carswell, whatever its shortcomings, does have medical staff on site. Make sure her conditions are documented and she is receiving treatment. That paper trail matters if any future release request ever does get filed.