We recently look in two kittens that had been living in a garden and have taken them to get their jabs done this week. Make sure you get the vet to check their ears and tell them they have already been outside.
As ours had been living in a garden, they had picked up ear mites (which I thought they might have after eventually getting close enough to them to look in their ears). Get them wormed and defleaed too as ours had both due to living in the garden and the person we got them from not having bothered to do either.
Our jabs cost us £59 for each kitten, which included one set immediately now and then another set in two weeks time.
We weren't sure exactly how old ours were when we got them either but the vet was helpful and weighed them etc and confirmed that they are now about 10 weeks old.
I hope they're both ok. If they are having trouble settling in, Feliway has worked wonders for helping our wee ferel beasties settle in, as for the first week or so, they just hid under the sofa and hissed at us if we tried to get close to them!