14 weeks Postpartum weight loss plateau

I for the life of me can’t shed the last 15lbs since postpartum week 7. I was always thin at 120lb, 5’7 with fast metabolism.

Gained 47 lbs during pregnancy - lost 20lbs after delivery then lost 12lbs the first seven weeks. Now I’ve been stuck with the last 15lbs! Some days I eat very little with just oatmeal bc I’m the sole caretaker and slammed so it’s confusing. I also pump and breastfeed and drink green juice and plenty water.

Occasionally I exercise but it makes no sense why no weight loss at all despite little food intake!