Usually no more that 2-3 weeks on the high side, several days on the low side. Relatives get approved quickly, the thing that takes time is the background check of the applicant. If you have a felony it will delay and probably invalidate your application.
https://www.inmateaid.com/ask-the-inmate/how-long-does-it-usually-take-to-be-approved-or-denied-for-visitation#answer
Accepted Answer Date Created: October 28,2015