Was Mary Drake NOT in Radley when she had spencer??

IN EPISODE 7X1 SPENCER TELLS THE GROUP THAT MARY DRAKE WAS IN AND OU OF RADLEY MOST OF HER LIFE AND GOT OUT PERMANENTLY  23 YEARS AGO (IRONICALLY THE AGE SPENCER IS).  WAS SHE IN RADLEY WHEN SHE HAD SPENCER? IF SHE WAS, THEN SHE WAS RELEASED WITHIN A YEAR OR MORE LIKELY MONTHS AFTER SPENCER WAS BORN. IF THE DOCTORS AT RADLEY DEEMED HER FIT FOR RELEASE THAT YEAR, WHY WASN'T SHE ALOUD TO, OR DIDN'T SHE WANT TO TAKE HER CHILD WITH HER??