Its a long standing problem and you're right SIL will always take her sons' side..he is now 20 years old. The money issue is because she is living beyond her means in the US and totally indulges her son now and in the past with anything he wants. She has bought him a car before now when he was 15 before he could even get a licence .The car just sat on the drive until she had to sell it again to fund her. So we won't be giving any money over anyway.