Which test
 

I’d like to ask an elderly lady with dementia to do a dna test to try and find a link to her grandmother from Ireland.

Is it ethical?

Do I ask her nominated next of kin - they aren’t family - we are - but I don’t have contact with them but others in family do.

If they agreed I wonder what the easiest test would be. I have an ancestry kit but would that be the easiest to use?

I don't think it would be right just to ask her, Julie, as she might not understand the implications; think it would be better to ask her nominated next of kin and if they say yes, then her.

Ancestry and 23 and Me both use saliva tests which might not be the best option in this case. According to the site linked below, Family Tree DNA and My Heritage both use cheek swabs which might be better. But check first before ordering!
https://www.smarterhobby.com/genealogy/best-dna-test/

I would not advise Living DNA since you will be unlikely to get matches from them.

Thanks Kate

Will ask the family to get in touch with the nok to see if they will agree.

Yes I think the cheek swab would be a lot easier especially after what Tom said about his several goes at getting an ancestry test done properly.

I think that you can do a different test with ancestry but you would need to contact them. I'm sure I've read on FB that those who have had issues with the saliva test were able to do it another way.