By all means try stable rest - but IME, exercise is generally good for their feet, in fact BH makes sure he gets any lame ones moving good and proper at least every other day
I do find the Charollais type a little more hypochondriac than some of the others. But also, we do get sheep here who go lame and there's nothing to see for some time. Most get better on their own, but some do go on and develop something we can treat. Once it's 'come out', then cleaning up and topical and systemic antiobiotics generally sort it - but we prefer to not use a/b's when we can't see a problem, unless she's so lame she can't get about.
One thing is that if you don't let her fight any infection herself, she won't develop immunity. There is a view that you should cull any sheep that has feet problems at all, ever, but we tend to only cull repeat offenders - and we don't get a lot that repeat, so it would seem that they do develop immunity, on the whole.