I had to look it up too
1 stone is equal to 14 pounds. So 3 stone is some serious progress...congratulations XKerry!
One other factor that may be coming into play is hormonal shifts from weaning the baby. Most experts recommend that breastfeeding moms increase calories by 200 and of course, once you wean, that 200 k is no longer necessary. Sometimes 5 small meals, including protein with each, helps. But as Cassie mentioned, might just need to be patient and change up your exercise routine. Hang in there and keep up the great work!