I’m wondering if France Services could help. They could certainly access the relevant parts of the law to confirm daughter in law is not covered by family protection.
Personally I’d be a bit worried that she might scarper and leave the son in the lurch too. Also, getting the money blocked from her moving it elsewhere. This is rhe sort of queation I’d ask France Services to look at first as time may be of tbe essence.
Then once France Servicea has checked the law and advised on any protective action while this is being sorted out, the next question is who can, and how, to approach her bank to get the money frozen if it’s still in her account (probably this is via their own bank but ask) , or how to secure whatever she had that could repay the money, while action is taken. It may be that denying the transactions initially with own bank could get the money suspended at both ends for a period.
Is the daughter in law French?
Are they absolutely certain, snd sticking to it, that they kept access codes secure at all times? The bank will push hard on this and they’ll have to stick to their guns.
Are you in your mind sure that if they think this has happened, there is no other explanation than theft? And are they absolutely sure it’s the daughter in law…is there any other possibility. The son may be involved, however painful this is. But step #1 is ro officially deny / dispute the transactions.
I’d leave the son out of it for now and not inform him if he’s being unhelpful.
As others have said getting which device was used, checked, might help, that can be done by bank’s IT. Also do they have any proof that they were not in a position or location at the time transactions were done, to have done them as this would help.
But I think the first thing is to get the question of family immunity removed and to formally deny tbe transactions with own bank and then if they’re very sure, make an official accusation.
Speed is of the essence and I’d make sure France Services tells how to make a complaint to gendarmes and both banks that they cannot ignore and that will force them to look at it. Ie what legislstion to quote, also send LRAR’s etc.
Keep a timeline with exact time, place, date, method of contact with anyone about this, what was said on either side.
There may be time limits so I’d want to get into the position of sending LRAR’s to banks and whatever method of complaint gendarnes can’t ignore or deny, asap. You may have to complain within x days or hours so even if I might have to send a further LRAR later, I’d be prepared to send starting ones to each (bank(s), whatever makes it impossible for gendarmes to ignore) now. I am pretty sure it’s called “Faire Opposition” on tbe transactions, to their own bank and there is a procedure in the t’s and c’s of the account for this, and possibly something to click in the app.