Should we separate my in-laws money when one goes into care?

Keep_pedalling

Don’t wait for it to rum out, contact her SW asap and explain the situation payments can be deferred until this is sorted out. You also need to for deputyship through the court of protection not only to get control of her accounts but to be able to deal with potential future major issues such as having to sell the house if anything happens to your father. Get his LPAs sorted as well.