First off, if you don't want to keep her, then don't feel the need to justify it, send her away.
However, if you want to keep her on, here are my thoughts.
Prolific
ewjbsdgksdbsbd - number of lambs - can be inherited, yes - but this year we and our neighbours have all had ludicrously high proportions of triplets, so we'd not count that against her (we try to breed out any tendency to triplets) this year.
She's small because she was a triplet. If she's still small next year when you want to tup her, then select her out at that point.
Two years ago our neighbour had all our orphan ewe lambs off us to rear as a foundation flock. We advised against it, saying that pet lambs usually don't make good mothers - in fact, they can be hard to get into lamb.
She took 6 anyway, and we tupped them for her last backend. The 6 had 9 lambs between them, of which one was born dead, and all 8 remaining were super lambs and have done very well. The ewes were no more nor no less good at mothering than any other gimmer ewe. The lambs are outstanding, several farmers in the area have commented on it. We smile wryly, and say, "Ah, well - they were well bred."

Dan, need emoticon for eating these words: "pet lambs usually don't make good mothers - in fact, they can be hard to get into lamb" - wrong wrong wrong!
