Replenishing the good will? Just two months after finalizing their divorce, Jennifer Garner and Ben Affleck reunited for a coparenting therapy session in Brentwood, Calif., on Dec. 4. “They may not be romantically linked anymore, but Ben and Jen will always be in each other’s lives, and that’s why they’re still in counseling,” explains a source close to the former couple, who share daughters Violet, 13, and Seraphina, 9, and 6-year-old son Samuel. “They’re doing it for the kids mostly, but it also helps them communicate better and co-parent more efficiently.” They also talk about “creating healthy boundaries,” the source notes, which is particularly important now that the 46-year-old Alias actress has gotten so serious with burger chain CEO John Miller that they spent Thanksgiving together. Jen and Ben, 46,…