I think pictures would be useful, but I think that what looks like a hole near her bag is 'normal' (believe it or not!)...
More of a worry is the wool pulling and bare patches etc. Best way forward really would be to get a vet to take a look - so that they can correctly diagnose lice or (which would be worse) scab. The danger of trying to diagnose by forum consensus (which, of course, we're all tempted to do at times...) is that with this sort of problem you can end up spending a lot of unnecessary time (& money) on pointless treatments...
Sometimes a vet can diagnose with a sample of wool and scraping of skin (ie doesn't need to see the actual sheep), but this can be more risky since you need very good samples to diagnose properly...
Also, a number of the possible conditions can spread fairly rapidly among the flock - so best to act as quickly and rapidly as you can...
Sorry not to be more diagnostic, but good luck.