My 14yr old has lived with me for nearly 4 years and I don’t get any help with money which I was ok with until last when I had to have 6 wks off work due to an operation , when I signed on I told universal credit he lived with me ,and they said I had to prove it with either a letter from a doctor dentist or his school , I tried his school but they said his mother had to notify them and the same with his doctor, I spoke to his mum and she refused to notify his school so I had to accept I couldn’t get the full allowance towards my rent paid . My son and I are now self isolating and I’m having to sign on to benefits again, being self employed I not sure what the government plan is and I need to claim what is due to me and my boy. Is there anything I can do to prove he lives with me?