Hi mel-lyn
There is not enough information in your post to give you a definitive answer, you need to contact your local Welfare Rights Organisation, who will be able to tale all your information into consideration; you can find your local Welfare Rights Organisation to help you with advice by clicking on the link below and putting in your post code, it will then come up with a MAP with a list of agencies.
advicelocal.uk In answer to your question about claiming Child Benefit, yes you can, you can get Child Benefit up to the age of 20 providing the young adult is in full time, non advanced education;
www.gov.uk/child-benefit.
Rather than your husband claim the Child Benefit, it may be easier if you claimed Child Benefit, but this is a question to ask your local Welfare Rights Organisation.
Gary