Temporary insurance cover help

http://ift.tt/2tXy9Y3 So this is the message that I receive after plugging in my details to get some temporary insurance on my mums car to use on holiday because she isn't a confident motorway driver.Few details about me in case it makes a difference 20 years old 2 years no claims discount I am insured with the insurer that I'm trying to get the temporary policy from (Admiral)So what gives? It says enter my age. I enter it and it gives me a rough price. It then tells me to fill a few more details about myself like names and addresses and driving licence numbers so that they can come up with an accurate price. That's when it gives me the error message saying that they can't cover me at this time and I can't work out why. Is there a minimum age required that I don't know about? It might be a long shot but I thought I would try this sub first incase anyone has had any similar experiences before calling them as I have work soon.Any help would be appreciated. I have tried other websites but the minimum time they allow is a 1 day policy, and that's ~£50. Admiral you can do as little as a couple of hours which is what I need for a really reasonable price via /r/cars http://ift.tt/2uVCnwt