Health Insurance for the over 70's?

Now that my 92 mother-in-law lives permanently in France I need a top- up insurance to go with her CMU. However, several large insurers have told me they can't start a new policy for someone over 70. Can anyone recommend a company that will? I am looking mainly for 'hospitlisation.' as she is relatively healthy and her medication extra costs are managable.

Thank you. I'll give them a try

Here's one for a start. Others can be found if you google "mutuelle santé 90 ans plus"