Well, first you have to find a Vet who is up to speed on a) foals, and foaling.
and b) Minis.
Without this there is no point in having a Vet to check the foal.
The mare, maybe, if you suspect or are worried something may be wrong- retained placenta etc- give a Vet a problem, as I have said in another thread, and they are away- problems are what they are qualified to deal with best.
Give a Vet a straightforward check up and they seem to think they need to do something to justify the bill- then you get unnecessary injections and goodness knows what.
So, unless I have reason to suspect something is wrong I have never had the Vet out.
With my first litter of pups I did take them in to be checked as I wanted Mama checked to make sure there were no more puppies, but I never did it again.
Waste of time and money, as it turned out.
I would , however, actively encourage anyone who is even remotely worried about anything involving foaling, and is new to it, to get a Vet out straight away, sometimes it is worth the bill to be told all is well and to be able to get a good nights sleep!!!