Are you sure she's going to have a 2nd? That first lamb is quite large.
I'd say, if she's not laying down and pushing or if she's settled down and isn't acting restless, she's probably done. Also, has she passed her placenta? If she has, then no more babies.
If you aren't sure if she's done, reach inside and feel for a nose and feet.
She passed placenta...BUT she laying down and pushing again. Lily is so restless and prancing around. Mammy stomach is flat on one side and huge on the other.
Which side is still big? Right side is where the baby hangs out, left is where the rumen is.
If she's passed the placenta, she should be all done. Sometimes they stretch and push and bit more after giving birth because they are still having a few contractions to shrink the uterus. She also could be uncomfortable after giving birth. She had a big baby.
If there is any question about whether there is another lamb in there, scrub up and check her. Or if you are uncomfortable doing it yourself, call the vet.