Hi Robert. They do have insurance in France. The issue is that given that they need to submit their visa application next week I am not sure if they can get their insurance to fill up the form in time (its france afterall)
I looked at the local insurance but that would cost them about 80K THB each which is quite a bit when they already have an insurrance. They plan to stay 4-5 months but it looks like the thai insurrance only offer 1 year premium.