if i read correctly your feeding baby bp's small adult mice? no wonder she regurged on you, buy small hoppers for now, small adult mice is way too big for them, after you get them eating hoppers regularly, watch to see when one hopper a week doesn't do it anymore then move up a size in mice, you'll be able to tell when 1 hopper a week isn't enough by them patroling their cage or other hungry signs before their next feed day hope this helps.
your feeding schedule should be once a week for babies, once every 10-14 days for adults, if you can't get him to eat one week, just skip it and wait till the next week, bp's can go months without food