I would be supportive of my DIL and tactfully suggest that she tries to become a bit closer to her mother, inviting her alone across to her home to see if she can find out what is really going on. Perhaps her mother is being bled dry by her new husband and she goes along with whatever he asks of her because she is terrified he will leave her she will be left alone. It may well be that if she knew her daughter and son were there to offer her the support she perhaps desperately needs, she may have the courage to say "NO!" to him when he asks for more money; holidays etc. Some times situations are not always what they seem on the surface, you have to dig deeper to discover what is really going on, so don`t be too judgemental of your DIL offer her the support she needs at this time, be her sound wall where she can bounce her thoughts and worries on.
Angela Rayner lashes out and calls Sunak “pint sized loser”.