Me either. I'm struggling to find anything and can't afford to sign up to Ancestry again at the moment
Ilona was 10 years old when she and her parents entered Belgium ( in 1957) as Hungarian refugees. No mention of a sibling there, so thinking he must have been born 1957+. Parents would have been around 20 when IK was born, so it's doubtful the brother will be older than her. I realise it is possible mum could have had a baby at around 17, but surely he would still have gone to Belgium with them.