Oh dear.
At least it's great that they are willing to give it a try.
What human meter do you use?
Are they doing it free hand or with a lancet device?
I have a friend that looks after George when I go away, she struggles with the meter I use most of the time, it requires a lot of blood, so I always swap and let her use my back up meter which uses much less blood. I wonder if that would help?
Can your friend see what they are doing?
Have you tried showing them some Utube videos, there are a few on the Hometesting Link Post
http://www.felinediabetes.com/FDMB/threads/hometesting-links-and-tips.287/
I found them really helpful, I watched a few until one just clicked with me.
I use the lancet device, because I find it easier, but I found that you do have to hold the ear firmly and press it up against the lancing device, if you don't then it won't prick the ear.
Does Harley sit still for them? George is a real pickle, he's very good for me sits still, but he really plays up for DH and my friend, DH is comfortable being firm with George as is my friend but she has had to wear gardening gauntlets, because he's been naughty and scratched her hand, there was so much blood that she didn't know which was his or hers


yet when I do it he sits and purrs away like all he's getting is an ear rub.
She found that it helped to give George a treat, before and after, I also recommended that she get him used to her handling his ears by sitting with him and tickling his cheeks and rubbing his ears, which he loves, that seemed to help, he has learnt to sit still for her.
Don't give up, it just takes some people longer to get the hang of it, and it must be harder when it's not your cat.