Are my two 7 week old kittens healthy?

the best thing is to bring them to the vet to get them vaccinated. this way the vet will give you a free cheek up and your kittens will have some defense against many diseases. the vet will probably have your kittens de-wormed. some kittens are more lay back but diarrhea could very well be worm infested kitten and the worms will feed off of the nutrients from the kitten so your kitten will not be healthy. you really should plan a visit to the vet for both kittens. the reality is sad but many kittens die and the best way to prevent this is by getting the vaccinations done. until your kittens are fully vaccinated do not let them near any other kittens/cats that are not vaccinated