<<I should be able to get a hold of them in a day or two..>>
Does this mean you didn't dip the umbilici in iodine? It is worth doing this even with 'wild' sheep as it prevents infection from travelling up the torn cord into the bloodstream. With Soays you can catch them just after they are born to do this, especially if there are two of you - and check the sex at the same time. A very wild mother might run off but if you make the lambs squeak a bit she will come back once you've backed off. Sometimes you can see the tiny scrotum from the back, or you can look at their heads and see that males have bigger horn buds than females - you can't really see Soay ewe lamb horn buds when they are first born.
The 'au pair' ewe is interesting. At first I thought from your description that she was trying to steal a lamb, which is common when two ewes are labouring at the same time, but now I wonder if they are mother and daughter, as family ties continue forever in sheep.
I hope they carry on doing well